CI Atlas · Case library
Clinical case library
All 506 interactive cases from across the atlas, gathered in one place and grouped by module. Each vignette poses a real decision; choose an option to reveal the reasoning and the teaching point. To study a case in its full context, follow the module link. For self-test questions, see the self-assessment page.
Module 1 · Overview — a 200-year idea
A senior colleague, reflecting on the field, remarks that the cochlear implant was 'an overnight breakthrough of modern bioengineering' and that its acceptance was always inevitable once the electronics existed.
What is the most accurate historical correction to offer?
Module 2 · Volta & the first electrical hearing
A student asks how it can possibly be true that a deaf person 'hears' through a cochlear implant when no sound is entering the ear in the normal way.
Which principle, first glimpsed in Volta's experiment, best answers this?
Module 3 · Djourno & Eyriès — the 1957 first
A trainee examining a modern implant notes there is no wire or plug crossing the skin — power and signal somehow pass through intact skin to the internal device.
Which 1957 design feature does this modern arrangement directly inherit?
Module 4 · William House & the single-channel implant
Reading a historical chart, you find a 1978 adult fitted with a single-channel House/3M implant who was 'delighted' with it, yet whose notes record that he could not understand speech on the telephone.
How do you reconcile the delight with the poor speech score?
Module 5 · The single- vs multi-channel debate
A cost-conscious administrator asks why the programme uses multichannel implants when a simpler single-electrode device would be cheaper and more reliable, and 'sound is sound'.
What is the strongest physiological justification?
Module 6 · The American multichannel pioneers
Reviewing the history, a trainee is puzzled that the Utah Ineraid used a percutaneous (skin-penetrating) plug when transcutaneous coils were already known to reduce infection risk.
What made the percutaneous design valuable despite its drawback?
Module 7 · Graeme Clark & the Nucleus implant
Clark's 1978 first multichannel patient, Rod Saunders, had been deafened as an adult and could use the device to help understand speech relatively quickly.
Which factor most plausibly helped him succeed early?
Module 8 · The European devices — Chouard & MED-EL
A new audiologist asks where the three implant brands your programme uses actually came from, having heard the implant called 'an Australian invention'.
Which statement is historically accurate?
Module 9 · The speech-coding breakthrough
A historical report describes implant users whose speech scores improved markedly after a software update, with no change to their implanted electrodes or surgery.
What most likely explains the improvement?
Module 10 · FDA approval & the 1988 NIH consensus
A student lists the FDA milestones (1984 single-channel adults, 1985 multichannel adults, 1990 children) and asks which was the most significant for the science of hearing.
Which approval connected the implant most directly to brain development?
Module 11 · Widening the indications
An adult has normal low-frequency hearing but a steeply sloping severe-to-profound high-frequency loss, and struggles with speech clarity. Decades ago her residual hearing would have excluded her from implantation.
Which modern expansion of indications applies?
Module 12 · The implant goes global
A health official planning a state cochlear-implant scheme for deaf children asks why an indigenous or Chinese-made device — rather than the most feature-rich Western implant — might be the right choice for the programme.
What is the strongest argument?
Module 13 · From milestone to mainstream
A trainee, impressed that the implant is the most successful neural prosthesis with over a million recipients, concludes that the cochlear-implant story is essentially complete.
What is the most important qualification to that view?
Module 1 · Overview — the hearing pathway
A medical student watching a cochlear-implant clinic asks why the device is placed in the cochlea at all — why not amplify sound into the ear like a hearing aid, or fix the middle ear? The recipient has a profound sensorineural loss from hair-cell death, with a normal middle ear and an intact auditory nerve on imaging.
What is the best one-sentence explanation of why a cochlear implant works for this patient when a hearing aid does not?
Module 2 · Sound & acoustics
A patient with a sloping high-frequency hearing loss says she can hear that people are talking — she can tell when someone is speaking and roughly how loud — but she cannot make out the words, especially fast speech or unfamiliar names. Her low-frequency hearing is near normal.
Which acoustic feature of speech best explains why she hears that speech is present but cannot understand it?
Module 3 · Outer & middle ear
A candidate for cochlear implantation has a profound sensorineural hearing loss and, on top of it, a chronically discharging ear with ossicular erosion — a substantial conductive component as well (a large air–bone gap). The team worries the conductive problem will limit the benefit of an implant.
How does the conductive component affect the expected benefit from a cochlear implant?
Module 4 · Cochlear mechanics & tonotopy
During programming, the most apical electrode of a recipient's array reads an abnormally high impedance and is switched off. The recipient afterwards reports that the deepest, lowest sounds — the hum of an air-conditioner, the low notes of a male voice — seem less full than before.
Why does deactivating the most apical electrode preferentially affect low-frequency percepts?
Module 5 · Organ of Corti & hair cells
A child has a newborn hearing screen showing present otoacoustic emissions, yet the auditory brainstem response is absent and the child does not respond to sound. The pattern is consistent with auditory neuropathy spectrum disorder.
Present otoacoustic emissions with absent neural responses points to which cells working, and which step failing?
Module 6 · Mechanoelectrical transduction
A student notes that hair-cell transduction channels are pulled open mechanically by the tip links, rather than through a slow second-messenger cascade like many other sensory receptors. They ask what functional advantage this direct gating confers — and whether a cochlear implant can preserve it.
What is the main functional consequence of direct mechanical gating of the transduction channels?
Module 7 · The cochlear amplifier
A patient with a moderate sensorineural hearing loss describes a frustrating pattern: soft speech is inaudible, yet a slightly raised voice quickly becomes uncomfortably loud. A hearing aid that simply makes everything louder either leaves soft speech weak or makes loud sounds intolerable.
Which feature of cochlear physiology, lost in this patient, best explains the narrow band between 'inaudible' and 'too loud'?
Module 8 · Otoacoustic emissions
A newborn 'refers' (fails) on the otoacoustic-emission screen in one ear on day 1 of life. Repeat testing at three weeks, after the ear canal has cleared of vernix and amniotic debris, shows robust emissions, and diagnostic testing confirms normal hearing.
Why can a normally-hearing ear produce an absent otoacoustic emission at birth?
Module 9 · The auditory nerve
A new audiologist is struck that a cochlear-implant recipient's usable range — from a just-audible to an uncomfortably-loud electrical stimulus — is only a handful to a couple of dozen current units, whereas normal acoustic hearing spans more than 100 dB. They ask which feature of normal auditory-nerve coding the implant cannot reproduce.
Which property of the normal auditory nerve most explains its very wide dynamic range, and is absent in electric stimulation?
Module 10 · Coding of intensity & loudness
At a cochlear-implant fitting, the audiologist finds that increasing the current on an electrode by just a few units takes the recipient from 'I can barely hear that' to 'that's too loud'. The whole comfortable range spans only a small number of current units.
How does this electrical loudness behaviour compare with normal acoustic loudness coding, and why?
Module 11 · Coding of frequency & pitch
A successful cochlear-implant recipient understands conversation well, even on the telephone, but says music sounds flat and unmusical and she can no longer follow a melody or tell whether a note is higher or lower than another.
Which difference between normal and electric frequency coding best explains good speech but poor music and pitch?
Module 12 · Central auditory pathways
Two congenitally deaf children receive identical cochlear implants and have healthy auditory nerves on imaging. One is implanted at 10 months and develops age-appropriate spoken language; the other is first implanted at 8 years and, despite a well-functioning device, gains limited open-set speech understanding.
What best explains the very different outcomes despite identical devices and intact nerves?
Module 13 · Binaural hearing & localization
A bilaterally implanted adult reports a clear improvement understanding speech in noisy restaurants compared with one implant, but still finds it hard to tell exactly where a voice or a car is coming from.
Which binaural mechanism is most readily restored by two implants, and which is hardest, and why?
Module 1 · Overview — the plastic brain
Two children each have a profound congenital sensorineural hearing loss with an intact auditory nerve, and each receives the same model of cochlear implant. The first is implanted at 14 months; the second, whose loss was identified late, is implanted at 8 years. Three years on, the first is developing spoken language well while the second understands little speech, despite a well-functioning device and a normal MAP in both.
What best explains the large difference in outcome between these two children?
Module 2 · Critical & sensitive periods
A family of a 12-month-old with confirmed bilateral profound deafness asks whether they can postpone implantation for a few years until the child is older and 'better able to cooperate' with programming. There are no medical contraindications to early surgery.
What is the best counselling response, grounded in the biology of sensitive periods?
Module 3 · Lessons from the visual system
A child treated late for a dense unilateral congenital cataract has the lens removed and a clear optical image restored, yet remains functionally blind in that eye. Examination shows a structurally normal retina and a clear visual axis.
Why does restoring a clear image fail to restore vision in this eye, and what is the analogous lesson for cochlear implantation?
Module 4 · Competition & the pluripotent cortex
Two congenitally deaf children are implanted at the same age, but the first had several years of consistent hearing-aid use and an auditory-rich environment beforehand, while the second had no meaningful auditory input until the implant. The second child progresses more slowly, and imaging-based research in similar children shows visual responses in regions of auditory cortex.
Which principle best explains why prolonged auditory deprivation lowers the achievable outcome, even with an identical device?
Module 5 · The deaf brain — auditory deprivation
A researcher wants to know whether the cochlear-nucleus changes seen in deafness are caused by the loss of the sensory organ specifically, or simply by the loss of neural activity. In one group of developing animals the cochlea is removed; in another the cochlea is left intact but auditory-nerve activity is blocked pharmacologically. Both groups show very similar central changes.
What is the correct interpretation, and why is it encouraging for cochlear implantation?
Module 6 · Cross-modal plasticity
A prelingually deaf adult who has communicated by sign and lip-reading for decades receives a cochlear implant. The device works technically, but after a year they derive little open-set speech understanding, relying still on vision. Research imaging in similar patients shows strong visual activation of auditory cortical regions.
Which mechanism best accounts for the limited speech benefit, and what does it imply about timing?
Module 7 · The sensitive period for hearing
A congenitally deaf child implanted at 18 months is seen for follow-up. Cortical auditory evoked potentials show a P1 with a latency in the age-normal range. A second child, implanted at 8 years, shows a markedly prolonged, abnormal P1 that has not normalised after two years of device use.
What does the P1 latency tell you about each child's central auditory development, and why is it clinically useful?
Module 8 · The implant as environmental input
A sceptical trainee argues that a cochlear implant — a couple of dozen electrodes delivering a coarse electrical signal — could not possibly support normal-looking auditory development, given how unlike natural sound it is.
What is the best evidence-based rebuttal, grounded in the plasticity literature?
Module 9 · Age at implantation & outcomes
Two adults are referred. Patient A is 62 and lost all hearing 3 years ago from sudden sensorineural loss, having heard normally all their life. Patient B is 24 and has been profoundly deaf since birth, never having developed spoken language, and is now considering a first implant. A family member assumes the younger patient will do better.
Who is likely to derive more open-set speech benefit from implantation, and why?
Module 10 · Adult plasticity & rehabilitation
A postlingually deaf adult is activated and reports that voices sound robotic and unpleasant, and they are discouraged. The device is correctly programmed and the MAP is appropriate.
What is the best explanation and counselling, based on adult plasticity?
Module 11 · Binaural plasticity & bilateral CIs
A child implanted in one ear at 18 months did very well and used the device consistently. The family now asks about a second implant for the other ear, six years later. They expect the second ear to perform just like the first.
What should they be told about the likely binaural outcome, and why?
Module 12 · The paradox of plasticity
A student asks why evolution would let the brain's plasticity decline at all — surely a brain that stayed as plastic as a child's, able to learn anything and accept any prosthesis at any age, would be better.
What is the best conceptual answer, drawing on the paradox of plasticity?
Module 1 · Overview — deprivation & rescue
A student, having learned that deafness causes degeneration all the way up the auditory pathway, asks why a cochlear implant — which sits in the cochlea — could possibly help structures as far away as the cortex.
What is the best explanation?
Module 2 · The pathway in health
During counselling, a trainee is asked to point, on a diagram of the auditory pathway, to the exact structure a cochlear implant electrode stimulates.
Which structure is it?
Module 3 · Hair-cell loss & deafferentation
An ear has lost its hair cells to aminoglycoside ototoxicity. Months later the spiral-ganglion neurons are beginning to degenerate, even though the antibiotic never directly injured them.
What best explains the neuronal degeneration?
Module 4 · Spiral ganglion neuron degeneration
An adult has been profoundly deaf in one ear for over twenty years. A colleague doubts an implant could work, reasoning that 'the nerve must be completely dead by now'.
What does the degeneration time-course tell you?
Module 5 · The nerve & the electrode
At programming, most of a recipient's electrodes behave normally, but one mid-array contact needs very high current for any percept and produces a poor, unclear channel; raising its current only makes the sound spread and blur.
What is the most likely explanation, and the reasonable step?
Module 6 · The cochlear nucleus & the endbulb
A prelingually, long-deprived implant user does reasonably well for quiet speech but struggles markedly with the timing-dependent tasks — localisation and understanding speech in noise.
Which morphological change helps explain this?
Module 7 · Up the brainstem & midbrain
A child implanted in one ear at age 2 does very well. The family considers a second implant for the other ear, but only several years later, asking whether the delay matters.
What does the binaural brainstem biology predict?
Module 8 · The deprived auditory cortex
Two prelingually deaf adults are implanted. One was deaf only a few years; the other for decades, with imaging-style evidence of strong visual recruitment of the auditory cortex. The long-deprived patient does notably worse.
Which cortical mechanism best explains the difference?
Module 9 · Stimulation as a trophic signal
A trainee describes the cochlear implant as 'just a stimulator that lets a deaf ear hear'. A colleague adds that, in deafened animals, the stimulated ear keeps more neurons than the unstimulated one.
What biological principle does the colleague's point illustrate?
Module 10 · What stimulation restores — and its limits
A family asks whether the implant can 'repair' the damage deafness has done to their child's hearing pathway, or whether it only works around it.
What is the most accurate, honest answer?
Module 11 · From bench to bedside
Asked to justify implanting a deaf infant as early as safely possible, a trainee can only think of one reason (the brain's sensitive period).
What second, independent biological reason does this chapter add?
Module 12 · Protecting & rebuilding the substrate
A researcher proposes an electrode array that slowly releases a neurotrophin such as BDNF into the cochlea, alongside its normal stimulation.
What is the rationale, grounded in this chapter's biology?
Module 1 · Overview — counting hearing loss
You sit on a district health committee allocating a small ear-care budget. One member argues that hearing loss is 'not a real disease — nobody dies of it' and that the money should go elsewhere. You have the WHO and Global Burden of Disease figures in front of you.
What is the strongest evidence-based response to the claim that hearing loss does not merit public-health investment?
Module 2 · Measuring the burden — grades, prevalence & DALYs
Two patients each have a better-ear four-frequency average of 32 dB HL: a 40-year-old office worker and a 2-year-old child. The parents of the child are told the loss is significant and needs action; the adult is reassured it is mild and offered watchful follow-up.
Why do identical thresholds lead to different management, and is this consistent with WHO definitions?
Module 3 · The burden of hearing loss in India
A 4-year-old from a rural district is brought to a tertiary centre with no speech. The parents first noticed he did not respond to sound at about one year but were reassured locally that he would 'grow out of it'. Audiometry now confirms bilateral profound sensorineural loss.
Which feature of the Indian epidemiology does this case most exemplify, and what is its consequence?
Module 4 · Causes & risk factors in India
In a single rural ear-camp morning you see: a child with a chronically discharging ear and a perforated drum; a teenager whose hearing dipped after measles; a mill worker with high-frequency loss; and an infant with profound deafness whose parents are first cousins.
What do three of these four causes have in common that most shapes public-health strategy?
Module 5 · Chronic ear disease & preventable loss
A 6-year-old has had a left ear that 'always runs' for two years. Otoscopy shows a central perforation with mucopurulent discharge; the right ear is dry with a healed perforation. Audiometry shows a 35 dB conductive loss on the left, 25 dB on the right. His teacher reports he is falling behind and 'never pays attention'.
What is the correct framing of this child's hearing loss and its management priority?
Module 6 · Noise-induced loss & ototoxicity
A 9-month-old infant treated for a febrile illness with an aminoglycoside is found, weeks later, to have a profound bilateral sensorineural hearing loss. The mother mentions that her own brother 'went deaf after an injection' in childhood. The total aminoglycoside dose given was within normal limits.
What is the most likely explanation, and what would have prevented it?
Module 7 · Consanguinity & the genetics of deafness
First-cousin parents with normal hearing have two children, both with congenital profound sensorineural hearing loss; there is no other affected relative and no syndromic features. They ask why this happened and whether a future child would also be affected, and whether implantation will help.
What is the best explanation and counselling?
Module 8 · Congenital & childhood hearing loss
A child passed the newborn hearing screen at birth but is brought at two years with no speech and absent responses to sound; testing confirms bilateral severe-to-profound sensorineural loss. The pregnancy and birth were unremarkable. The mother had a mild flu-like illness in early pregnancy.
Which cause best explains a normal newborn screen followed by later-confirmed deafness, and what is the lesson?
Module 9 · Newborn & infant hearing screening
A baby born after a stormy neonatal-ICU course (prematurity, jaundice, ventilation) passed a cochlea-only OAE screen in the nursery. At 9 months the parents report no babbling and inconsistent responses to sound. Repeat testing shows present OAEs but a grossly abnormal ABR.
What does the OAE-present / ABR-absent pattern indicate, and what does it reveal about the original screen?
Module 10 · The global picture & projections to 2050
A health planner notes that global hearing loss is projected to rise from about 1.5 billion (2019) to 2.5 billion by 2050 and concludes that 'ear disease must be getting dramatically worse and prevention is failing'.
Is that interpretation correct?
Module 11 · The cost — economic, educational & cognitive
A family is weighing whether to pursue (and fund) a cochlear implant for their congenitally deaf toddler. A relative argues it is 'a lot of money just so he can hear a bit better' and not worth it.
What is the strongest evidence-based counter-argument?
Module 12 · Prevention & the cochlear-implant access gap
A tertiary centre can implant 200 children a year but its catchment contains an estimated several thousand eligible deaf children. Most who do arrive are older than ideal. The team debates where to direct limited effort to do the most good.
Which strategy best addresses the underlying problem revealed by this mismatch?
Module 1 · Overview — genes, deafness & the implant
Two unrelated 12-month-olds each have bilateral profound sensorineural loss and are referred for implantation. Their audiograms, ages and devices will be identical. The team wonders why published outcomes for such children vary so widely and whether anything can be known in advance.
What is the best account of why outcomes vary, and what could narrow the uncertainty before surgery?
Module 2 · Syndromic & non-syndromic deafness
A 10-month-old has congenital profound SNHL and is otherwise developing normally with no dysmorphic features, normal eyes on examination, and no family history. The parents are reassured it is 'just deafness'. Genetic testing is being considered before implantation.
Why might comprehensive genetic testing still change management in this 'isolated' case?
Module 3 · Patterns of inheritance
A child became profoundly deaf shortly after a standard dose of an aminoglycoside. The mother recalls that her own brother and a maternal cousin also 'lost hearing after injections'. No affected individuals appear on the father's side.
Which inheritance pattern does this suggest, and what is the practical lesson?
Module 4 · GJB2 & the connexins
A 14-month-old with congenital profound SNHL, normal imaging and no syndromic features is found on gene-panel testing to carry two pathogenic GJB2 (connexin-26) variants. The parents ask what this means for the likely result of implantation.
What can you tell them about the expected cochlear-implant outcome, and why?
Module 5 · The deafness-gene landscape
Two children with identical profound SNHL have genetic results: one carries two pathogenic SLC26A4 (pendrin) variants with an enlarged vestibular aqueduct; the other carries pathogenic TMPRSS3 variants. Both families ask what to expect from implantation.
How does the gene landscape let you counsel them differently?
Module 6 · Testing — from Sanger to next-generation
A child with congenital non-syndromic SNHL had single-gene GJB2 (Sanger) testing years ago, which was normal, and no further genetic work-up. The family returns and asks whether modern testing could add anything.
What does current technology offer that the earlier test did not?
Module 7 · Genetic testing in the CI work-up
A boy with congenital profound SNHL is being prepared for implantation. Preoperative gene-panel testing returns a pathogenic POU3F4 (X-linked, DFNX2) variant, and imaging shows an abnormal cochlea–internal-auditory-canal interface.
How should this preoperative genetic result alter the surgical plan?
Module 8 · The spiral-ganglion hypothesis
A trainee asks how genotype can predict implant performance when 'the deafness is the same'. You have one recipient with GJB2 deafness and one with the deafness-dystonia gene TIMM8A (Mohr-Tranebjærg), both profoundly deaf preoperatively.
What is the clearest way to explain the predicted difference?
Module 9 · Genotype-specific CI outcomes
A boy with progressive deafness, early dystonia and declining vision is found to carry a pathogenic TIMM8A variant (deafness-dystonia-optic-neuronopathy / Mohr-Tranebjærg). The family asks whether a cochlear implant will restore his hearing as well as it did for his cousin with GJB2 deafness.
What should you tell them about the likely implant outcome, and why does it differ from the cousin's?
Module 10 · Auditory neuropathy & OTOF
An infant has present OAEs but absent ABRs — auditory neuropathy. The team is hesitant to implant, fearing a disordered nerve will give a poor result. Gene-panel testing returns biallelic OTOF (otoferlin) variants.
How does the OTOF result change the team's expectation?
Module 11 · Counselling, recurrence & ethics
A funding committee proposes using genetic results to deprioritise implantation for candidates whose genotype predicts a poor outcome, citing cost. A family whose child carries a spiral-ganglion-gene variant is worried they will be refused.
What is the most defensible position on using genotype this way?
Module 12 · Gene therapy & the genomic future
Parents of a child with GJB2 deafness read that gene therapy has restored hearing in children with OTOF mutations and ask why their child cannot have the same gene therapy instead of an implant.
What is the most accurate explanation of why OTOF was treatable first and GJB2 is harder?
Module 1 · Overview — why the cause matters
Two adults are referred for implantation with identical bilateral profound, flat sensorineural audiograms. One was deafened by gentamicin; the other by bacterial meningitis ten years ago. The team is asked whether the identical audiograms mean identical prospects.
What is the best reason their prospects may differ?
Module 2 · Where the lesion sits
A child has absent otoacoustic emissions, absent ABR, but is suspected of having a lesion at the auditory nerve rather than the hair cells. The family asks whether a cochlear implant can help if the problem is 'the nerve'.
How should the site of lesion guide the answer?
Module 3 · Congenital & perinatal causes
A premature baby who spent weeks in intensive care — with hypoxia, jaundice and a course of gentamicin — fails the automated-ABR screen. The parents are told otoacoustic emissions were actually present in one ear.
What does the OAE-present, ABR-absent pattern suggest, and why was AABR the right screen here?
Module 4 · Meningitis & cochlear ossification
A 3-year-old is discharged after pneumococcal meningitis and found to have bilateral profound hearing loss. The implant clinic can offer an assessment in four months as a routine referral.
What is the correct response to the proposed timeline?
Module 5 · Congenital CMV & in-utero infections
A toddler who passed the newborn hearing screen is brought back at 18 months with delayed speech and a newly identified moderate-to-severe loss. Stored newborn dried blood spot testing returns positive for CMV.
How does the CMV result reframe the picture?
Module 6 · Ototoxicity — drugs that damage the ear
A young adult became profoundly deaf within days of a single standard dose of an aminoglycoside for an infection. Her mother and a maternal uncle also lost hearing after antibiotic injections.
What is the most likely explanation, and its practical implication?
Module 7 · Noise-induced hearing loss
A factory worker complains of great difficulty following conversation in noisy rooms, yet his pure-tone audiogram is essentially normal apart from a shallow 4-kHz notch.
Which concept best explains the mismatch?
Module 8 · Presbycusis — the ageing cochlea
Two 78-year-olds have similar moderate-to-severe downsloping audiograms, but one scores far worse on word recognition than the other and gains little from hearing aids.
Which presbycusis subtype likely explains the poor word scores, and why does it matter for implantation?
Module 9 · Sudden & autoimmune hearing loss
A 40-year-old reports hearing worsening in both ears over two months, fluctuating, now moderate-to-severe. Examination and imaging are unremarkable; she has a history of another autoimmune condition.
What is the key diagnosis to consider, and why is it urgent?
Module 10 · Ménière's & cochlear otosclerosis
An adult with far-advanced otosclerosis is implanted and, at activation, several electrodes produce visible facial twitching at comfortable loudness levels.
What explains the facial stimulation, and how is it managed?
Module 11 · What the temporal bone reveals
A trainee asks whether a pre-operative test can tell exactly how many spiral-ganglion neurons a candidate has, citing temporal-bone studies that link survival to cause.
What is the honest answer?
Module 12 · From cause to candidacy
Two children are listed for implantation: one with confirmed GJB2 deafness, one deafened by meningitis four months ago with CT showing early basal-turn ossification. Resources allow one to be expedited.
Which should be prioritised, and on what principle?
Module 1 · Why Electric Hearing Is Different
A 54-year-old man, deafened in adulthood, is activated four weeks after surgery. With his hearing aids he had described sound as 'too quiet'. At switch-on he reports the implant's sounds as oddly mechanical and says a small turn of the volume control swings rapidly from inaudible to uncomfortable. His audiologist reassures him these are expected features of electric hearing rather than a fault.
Which statement best explains, in psychophysical terms, why a small change in the control swings him from inaudible to uncomfortable?
Module 2 · From Acoustic to Electric: What Is Lost in Translation
A keen amateur pianist receives an implant and recovers excellent speech understanding within months. She is delighted with conversation but disappointed that music sounds flat and metallic, with melodies hard to follow even though she can tell when music is playing. Her audiologist explains that this contrast between good speech and poor music reflects what electric stimulation can and cannot recreate.
Which lost feature of acoustic hearing best accounts for her poor music perception despite good speech?
Module 3 · The Electric Dynamic Range: A Few Decibels to Work With
During a programming session an audiologist is in a hurry and sets the comfort (C) levels only slightly above the measured threshold (T) levels across all electrodes, leaving a very small T-to-C span. The patient reports that everything sounds either inaudible or instantly too loud, and that quiet speech disappears while loud speech is harsh. Impedances and the device check are normal.
What is the most likely explanation and corrective action?
Module 4 · Steep and Fast: How Loudness Grows with Electric Current
During a follow-up map, a 6-year-old implant user flinches and covers the device whenever one mid-array channel is stimulated, even though its measured upper level was set only 8 current units (about 1 dB) above its neighbours at the previous visit. Single-channel loudness scaling shows this channel jumps from 'medium' to 'too loud' over a span barely wider than its neighbours.
What best explains the flinch and guides the fix?
Module 5 · The Processor Must Do What the Cochlea No Longer Can
An adult cochlear implant user scores well on sentences in quiet but complains that in a busy cafeteria speech becomes inaudible the instant the room is noisy, even when the talker is close. Her map uses a wide input dynamic range and a long AGC release time.
Which adjustment is most likely to help, and why?
Module 6 · Just Detectable: What Sets the Electric Threshold
A clinician measures behavioural T-levels for a new program using single pulses at a low rate and a short phase duration, then loads the patient's everyday program, which uses a high stimulation rate and a longer phase duration. The patient reports that soft sounds are now far too loud and the overall map feels harsh.
What is the most likely explanation?
Module 7 · Reading the Envelope: Temporal Processing in Electric Hearing
A 58-year-old man implanted two years ago scores 85 percent on sentences in quiet but drops to 25 percent in background babble. Impedances are stable, his map is loud enough and comfortable, and electrode imaging shows good placement. On research testing his modulation-detection thresholds are poorer than average and worsen sharply when a competing noise is added.
What best explains the gap between his quiet and noisy performance?
Module 8 · Pitch from Timing: The 300-Hz Ceiling
A native Mandarin speaker with a well-fitted unilateral implant understands English sentences in quiet at 80 percent but frequently confuses Mandarin lexical tones and cannot follow the melody of familiar songs. Research pitch-ranking shows her perceived pitch stops increasing once pulse rate exceeds about 250 Hz.
Which limitation best accounts for her tone and melody difficulties?
Module 9 · Pitch from Place: Tonotopy, Mismatch, and the Map
A 45-year-old woman activated last month with a shallow electrode insertion reports that all voices, including her own, sound unnaturally high-pitched and tinny, and music is unpleasant. Speech testing in quiet is steadily improving. Imaging confirms the array does not reach the apical turn, and she is using the manufacturer's default frequency allocation.
What is the most likely explanation for the high, tinny voice quality?
Module 10 · Blurred Frequencies: Spectral Resolution and Current Spread
A 58-year-old man with a 22-electrode implant scores 92% on CNC words in quiet but drops to 28% on sentences at +10 dB SNR. His aided detection thresholds are excellent and impedances are normal. A spectral-ripple discrimination test shows a threshold of about 0.8 ripples per octave, far below the typical normal-hearing range.
Which interpretation best explains this profile?
Module 11 · When Channels Talk to Each Other: Channel Interaction
During a research session a CI user is asked to pitch-rank single-electrode stimuli. She reliably orders most contacts from low to high, but a pair of adjacent apical electrodes are indistinguishable to her no matter how the levels are set. Forward-masking measurements show an unusually broad spatial tuning curve over that region.
What does this finding most directly indicate, and what is a reasonable response?
Module 12 · Twelve Wires, Eight Voices: The Number of Effective Channels
A clinician compares two postlingually deafened adults: one has a 12-electrode device, the other a 22-electrode device of a different brand. Both are experienced users with good nerve survival. Their sentence-in-noise scores at matched SNR are nearly identical. The trainee asks why the extra ten electrodes did not give the second patient a clear advantage.
What is the best explanation?
Module 13 · Why Speech in Noise Is the Hardest Test
A 58-year-old man implanted three months ago scores 94 percent on monosyllabic words in quiet and is thrilled in one-to-one conversation. He returns angry, saying the implant 'stopped working' at his daughter's wedding, where he could not follow anyone at the table despite the booth scores.
What is the best explanation and first response?
Module 14 · Why Music Is the Hardest Signal of All
A 46-year-old former amateur pianist is six months post-activation with excellent speech scores in quiet. She reports she can tell when music is playing and can tap to the beat, but every song sounds the same, she cannot recognise melodies she has played for decades, and instruments are indistinguishable. She asks whether her implant is faulty.
Which statement best explains her experience?
Module 15 · Measuring Electric Hearing, and Using What You Find
An audiologist is deciding whether to enable a current-focusing (tripolar) program for two adult users. User A has broad forward-masked spatial tuning curves and a poor spectral-ripple threshold but normal modulation-detection thresholds. User B has sharp tuning and good ripple scores but poor modulation detection across several mid-array electrodes.
How should the psychophysical findings guide the decision?
Module 1 · Overview — recreating hearing
A family asks why their child, implanted with the same device and surgery as a friend's child, was switched to a different sound-coding strategy and processor settings — and whether the operation or the software matters more for how well she hears.
What is the best framing of the answer?
Module 2 · What normal hearing does
An adult does superbly on speech testing in a quiet booth but says music sounds flat and tuneless and she cannot follow conversation in a noisy restaurant. She wonders whether her implant is faulty.
How do the functions of normal hearing explain this pattern?
Module 3 · The processor's signal path
A trainee is shown that a recipient's processor has a directional microphone, an ACE coding strategy, and individualised T and C levels, and is asked to place each of these in the processor's signal path.
Which ordering matches the signal path from sound to current?
Module 4 · Filter banks & the place code
After activation, a postlingually deaf adult reports that voices sound unnaturally high-pitched and 'cartoonish'. Imaging shows the array is inserted only part-way, sitting more basally than a full insertion.
What explains the percept, and what helps over time?
Module 5 · Envelope, fine structure & the vocoder
A student is surprised to learn that normal-hearing listeners can understand sentences from noise-vocoded speech carrying only the envelopes of four frequency bands, and asks what this implies for cochlear implants.
What is the correct implication?
Module 6 · CIS — the breakthrough
A historian of the field notes that around 1991 speech results from multichannel implants improved sharply, yet the electrode arrays had not changed. She asks what produced the leap.
What was the key change?
Module 7 · Channel interaction & current spread
A trainee asks why activating all 22 electrodes does not give 22 independent channels of information, and why adding electrodes beyond a point stops helping speech.
What is the explanation?
Module 8 · Peak-picking — SPEAK & ACE
A recipient programmed with ACE asks why his processor stimulates only some of the analysis bands each cycle rather than all of them, worrying that information is being thrown away.
What is the rationale for peak-picking?
Module 9 · Fine structure & temporal coding
A recipient using a fine-structure strategy notices that the literature describes the fine-timing cues being applied only to the low-frequency (apical) channels, and asks why it is not used everywhere.
Why is fine-structure coding limited to the apical channels?
Module 10 · Current focusing & virtual channels
An engineer explains that by driving two adjacent electrodes together with a chosen current ratio, a recipient can perceive a pitch between the two single-electrode pitches. A trainee asks what this technique is and what it buys.
Which best describes it?
Module 11 · Front-end pre-processing
A recipient struggles in restaurants. The audiologist enables an adaptive directional microphone and noise-reduction program, and his speech-in-noise improves markedly, even though the coding strategy was unchanged.
Why did a front-end change help so much?
Module 12 · The future of sound coding
A researcher claims that optogenetic stimulation might one day give cochlear implants hundreds of independent channels. A sceptical trainee asks why light could succeed where more electrodes have not.
What is the core argument — and the main caveat?
Module 1 · Overview — the limits of amplification
An adult with severe sensorineural loss returns frustrated: her new hearing aids are well fitted to her audiogram and everything sounds loud, yet she still cannot follow conversation. The audiologist confirms every frequency is now audible.
What best explains the mismatch between audibility and understanding?
Module 2 · Beyond the audiogram
Two patients have superimposable audiograms. One does well with hearing aids; the other gets almost nothing from them. A trainee asks how the same audiogram can predict such different outcomes.
What is the explanation?
Module 3 · Audibility — what amplification does
A patient misses soft, high-frequency consonants like /s/ and /f/. The audiologist applies a prescriptive formula that adds extra high-frequency gain, and word recognition improves — up to a point, beyond which more gain causes discomfort.
What principle does this illustrate?
Module 4 · Recruitment & the narrowed dynamic range
A patient with a 90 dB loss constantly adjusts the hearing-aid volume: soft speech is inaudible, but a slightly louder talker becomes intolerably loud. He has largely stopped wearing the aids.
What phenomenon is responsible, and what does Boothroyd's formula predict here?
Module 5 · Why recruitment happens
A patient with severe recruitment that made hearing aids unbearable is implanted, and afterwards reports that loudness feels far more controlled and comfortable across a wide range of sounds.
Why does electrical hearing avoid the recruitment that plagued the hearing aid?
Module 6 · Blurred frequency resolution
A patient confuses similar-sounding words even when speech is comfortably audible. Testing suggests broadened auditory filters. The audiologist tries a spectral-enhancement program that sharpens spectral peaks, with little benefit.
What underlies the difficulty, and why did spectral enhancement disappoint?
Module 7 · Reduced temporal resolution
A hearing-aid user manages one-to-one in a quiet room but cannot follow conversation at a noisy party. Testing shows reduced temporal resolution.
Why does the noisy setting collapse her understanding?
Module 8 · Cochlear dead regions
A patient with measurable high-frequency thresholds gets no benefit from high-frequency amplification, and finds speech clearer when the highs are turned down. A TEN test reveals a high-frequency dead region.
What does this finding mean for the fitting?
Module 9 · Audibility vs distortion
A patient's aided speech score has plateaued: making speech fully audible across the spectrum no longer improves understanding, and increasing compression seems to make noise worse.
How is this best understood?
Module 10 · When a hearing aid has done all it can
A patient with a severe loss has worn well-fitted hearing aids for six months. Unaided audiometry looks 'aidable,' but aided sentence testing in quiet and noise shows poor scores. The family asks whether to keep adjusting the aids.
What is the most appropriate next step?
Module 11 · When the lesion changes the calculus
A child has present otoacoustic emissions but absent ABR and very poor speech understanding with well-fitted hearing aids. The diagnosis is auditory neuropathy spectrum disorder.
Why do hearing aids disappoint here, and what is the implication?
Module 12 · From hearing aid to implant
A patient asks why a cochlear implant should help when years of ever-more-powerful hearing aids did not. The clinician explains the fundamental difference between the two devices.
What is the key difference that lets the implant succeed?
Module 1 · The test battery & cross-check
An infant's OAEs are robustly present, but the ABR shows no replicable wave V even at high levels. A trainee is tempted to accept the OAEs as proof of normal hearing.
How should the conflicting results be interpreted?
Module 2 · Pure-tone audiometry & calibration
A clinician uses adult RECD assumptions to set levels for a 4-month-old infant. The aided fitting later seems too loud.
What was the methodological error?
Module 3 · Masking — isolating the test ear
A right ear with a 75 dB air-conduction threshold is tested with supra-aural phones; the left ear has normal bone conduction. No masking is applied.
Why might the recorded right-ear threshold be invalid?
Module 4 · Bone conduction & the air–bone gap
A child has a low-frequency air–bone gap but a normal tympanogram, normal otoscopy, and supranormal bone-conduction thresholds. Imaging shows an enlarged vestibular aqueduct.
How is the air–bone gap best explained?
Module 5 · Speech audiometry & rollover
An adult's word-recognition score peaks at 64% at a moderate level, then falls to 40% when the level is raised further. The audiogram is symmetric.
What does this pattern suggest?
Module 6 · Tympanometry & immittance
Two children each have a flat (Type B) tympanogram. One has a normal ear-canal volume; the other a very large volume.
How do their middle-ear states differ?
Module 7 · The acoustic reflex
An adult referred as a possible implant candidate is found to have acoustic reflexes present at essentially normal levels at 500, 1000 and 2000 Hz.
What does this finding imply?
Module 8 · Otoacoustic emissions
A newborn passes the OAE screen but later shows profound deafness on diagnostic ABR, with a cochlear microphonic that inverts with stimulus polarity.
What is the diagnosis?
Module 9 · The auditory brainstem response
As the click level is lowered during a threshold ABR, the early waves disappear while one later peak persists down toward threshold.
Which wave is it, and why does it matter?
Module 10 · ASSR, ECochG & cortical responses
Tone-burst ABR shows no response at the equipment maximum (~95 dB), leaving the team unsure whether the child has a severe or profound loss — a distinction that affects device counselling.
Which test best resolves this?
Module 11 · Paediatric behavioural audiometry
A 4-month-old 'responds' to sounds around 60 dB on behavioural observation. A clinician proposes to set hearing-aid gain from these levels.
Why is this inappropriate?
Module 12 · Paediatric speech perception
A 3-year-old implant user has limited expressive vocabulary. The audiologist must pick a speech-perception measure.
What is the appropriate choice and caveat?
Module 13 · Speech-in-noise & valid testing
An implant user scores 92% on sentences in quiet but struggles badly in a restaurant. The clinic wants a test that reflects this.
What testing approach captures the problem?
Module 14 · Real-ear measurement & verification
A child makes poor progress with hearing aids. Before concluding the aids are inadequate and moving toward implantation, the team reviews the fitting.
What verification step is essential first?
Module 15 · Loudness, tinnitus & non-organic loss
An adult claims a 70 dB loss on behavioural testing, but the SRT is 25 dB, OAEs are present and the ABR shows normal thresholds. There is a compensation claim.
How should this be handled?
Module 16 · Self-report & functional outcomes
An implant user has excellent booth scores but feels the device has not helped with the one thing they wanted — conversations at work.
What tool best captures and addresses this?
Module 17 · Tele-audiology & the future
A remote region has many people with possible hearing loss but no sound booth or resident audiologist. A screening programme is planned.
What is a sound tele-audiology approach and its key caveat?
Module 18 · Putting the battery together
Results: no air–bone gap, Type A tympanogram, elevated reflexes, OAEs absent above 35 dB, recruitment on loudness growth, no rollover.
What is the site of lesion?
Module 1 · Overview — will the implant beat the aid?
A 58-year-old with a severe loss asks whether she should have a cochlear implant. Her hearing aids are well fitted but she struggles. The team frames the decision for her.
What is the central question candidacy must answer?
Module 2 · How the criteria evolved
A patient with a 55% best-aided sentence score is referred. A trainee recalls that years ago candidacy required essentially no open-set speech, and assumes the patient cannot qualify.
How should the trainee's assumption be corrected?
Module 3 · The audiological battery
A patient scores surprisingly well when the audiologist reads sentences aloud across the desk, but does poorly with recorded materials through the loudspeaker. The clinic must decide which result to use.
Why is the recorded test the valid one for candidacy?
Module 4 · Audiometric criteria & level
A borderline patient scores 70% on aided sentences at 70 dB SPL but only 40% at 50 dB SPL. The clinic debates which level should inform candidacy.
Which level is more appropriate, and why?
Module 5 · Speech-in-noise & valid testing
An adult scores 78% on aided sentences in quiet but reports they cannot follow conversation in any restaurant. A trainee proposes to record only the quiet score for candidacy.
What is the right approach?
Module 6 · Regulation & reimbursement
An evidence-based off-label implant is proposed for a Medicare patient whose best-aided score is above the CMS criterion. The surgeon asks whether the FDA permits it.
What is the binding constraint here?
Module 7 · Predicting the outcome
Two adults have identical audiograms and aided scores. One has been profoundly deaf for 2 years, the other for 30 years. The team counsels them on likely outcomes.
What most distinguishes their predicted outcomes?
Module 8 · The actuarial odds model
Two ears in one patient have identical aided sentence scores, but the right has been deaf 5 years and the left 28 years. The team uses an actuarial model to decide.
What does the model conclude?
Module 9 · Medical & otologic assessment
A candidate who meets the audiological criteria has active chronic suppurative otitis media with a draining ear. The surgeon considers the implications for implantation.
What is the appropriate course?
Module 10 · Imaging in the work-up
A child with profound deafness has, on MRI, an absent cochlear nerve in the internal auditory canal. The cochlea looks normal on CT. The family asks about an implant.
How does this finding affect candidacy?
Module 11 · Vestibular assessment
A candidate's better-hearing left ear has a normal caloric response; the right ear is profoundly deaf with an absent caloric response. Imaging is otherwise unremarkable.
How should vestibular findings inform the plan?
Module 12 · Paediatric candidacy
A 10-month-old with profound loss on ABR cannot yet give reliable behavioural responses. The parents ask how candidacy can be decided without a speech test.
How is candidacy judged in a child this young?
Module 13 · The expanding indications
A patient has a single profoundly deaf ear with troublesome tinnitus and a normal contralateral ear. A CROS aid helped only a little. They ask whether an implant is possible.
Is this patient a candidate, and why?
Module 14 · Cognition, dementia & the elderly
An 86-year-old, ASA II, with mild memory complaints is denied referral by a clinician who assumes age and cognition rule out implantation.
How should this be reconsidered?
Module 15 · Psychosocial assessment & expectations
A motivated candidate states confidently that the implant will restore normal hearing the moment it is switched on. Otherwise the work-up is favourable.
What is the most important step before proceeding?
Module 16 · Cost, funding & access
An audit finds that only a small fraction of eligible severe-to-profound patients in a region are implanted, and that under a tight budget only the 'most obvious' candidates proceed.
How should this be interpreted?
Module 17 · Counselling, ethics & consent
Deaf parents who use sign language are ambivalent about implanting their deaf infant. The team must navigate the decision.
What does ethical candidacy require here?
Module 18 · Which ear, one or both
A candidate has a poorer right ear and a better (but still failing) left ear. The trainee assumes the better left ear should be implanted to maximise the result.
What does the evidence suggest about ear choice here?
Module 19 · Bilateral & bimodal candidacy
A child does well with a first implant. The family asks whether a second is worthwhile and whether timing matters.
What is the best advice?
Module 20 · The team decision
At the multidisciplinary meeting, a referred adult is found to gain substantially more from a revised hearing-aid fitting than expected, with good aided speech. The team considers the decision.
What is the appropriate outcome?
Module 1 · Our Philosophy: The Rational Checklist
A 3-year-old with congenital profound sensorineural hearing loss and no risk features is referred for cochlear-implant work-up. The unit's standing default is to obtain both a high-resolution CT and an MRI under a single anaesthetic.
Applying the MRI-predominant, selective-HRCT protocol, what imaging is indicated?
Module 2 · Imaging as the surgical blueprint
A clinically straightforward adult candidate has imaging that shows a normal cochlea but raises a question about the cochlear nerve. The team asks what imaging is for.
What are the two jobs preoperative imaging does?
Module 3 · HRCT technique & planes
A trainee reformats a temporal-bone CT in the true axial (horizontal) plane and struggles to follow the structures.
What is the correct temporal-bone axial plane?
Module 4 · MRI sequences & the nerve view
A child with profound loss has a normal CT. The team wants to confirm the cochlear nerve is present.
Which imaging best answers this?
Module 5 · Normal temporal-bone anatomy
A learner cannot tell whether a cochlea is malformed because they are unsure what normal looks like across the planes.
What grounds the reading of malformations?
Module 6 · Cochleovestibular malformations
Imaging shows complete absence of the labyrinth in one child and a common cavity in another. The team must decide CI vs ABI.
How do these differ?
Module 7 · Hypoplasia, IP & EVA in detail
Imaging shows an incomplete partition type III (modiolus absent, septa present, bulbous IAC). The surgeon plans accordingly.
What should be anticipated?
Module 8 · Cochlear nerve, IAC & the ABI boundary
A child with profound deafness has a normal-sized internal auditory canal on CT. The family is told the nerve must be fine.
Why is that reassurance premature?
Module 9 · Ossification & fibrosis — patency
Six weeks after meningitis, a candidate's CT shows a normal-looking cochlea, but the team suspects early obstruction.
What is the best next step?
Module 10 · The facial nerve
In a child with cochlear aplasia, the CT shows the labyrinthine facial segment running anteriorly. The surgeon reviews the approach.
Why does this matter?
Module 11 · Middle ear, mastoid & vessels
Preoperative CT shows a high, dehiscent jugular bulb overlying the round-window niche.
What is the significance?
Module 12 · Measurements & electrode selection
Imaging measures a hypoplastic cochlea with a duct length of ~20 mm and an intact-looking modiolus is absent.
What array does this imply?
Module 13 · Paediatric imaging & radiation safety
An infant with profound loss needs imaging. A clinician proposes CT alone to avoid a general anaesthetic.
What is the correct approach?
Module 14 · Intra-operative imaging
During implantation of a common-cavity malformation, the surgeon is unsure the array is staying in the cavity.
What helps in real time?
Module 15 · Post-op electrode position
A postoperative image shows the array tip doubling back near the apex.
What complication is this, and why does it matter?
Module 16 · MRI compatibility of the implant
An implant recipient develops a contralateral vestibular schwannoma needing serial MRI surveillance.
What is true about scanning them?
Module 17 · Recent & emerging imaging
A centre wants the most accurate, lowest-dose way to confirm electrode scalar position after surgery.
Which modality is best suited?
Module 18 · The structured report
A radiologist completes a detailed preoperative scan review and writes a long list of findings.
What must the report end with to be useful to the surgeon?
Module 1 · Anatomy of a Cochlear Implant System
A patient with a 10-year-old implant asks whether she needs new surgery to get the latest sound-coding strategy.
What is the best answer?
Module 2 · From Sound to Nerve: The End-to-End Signal Path
A student traces the path from microphone to nerve and asks which stage is the coding strategy.
Which stage is purely software?
Module 3 · The Transcutaneous Link and Telemetry
Intra-operatively the surgeon cannot obtain back telemetry from the implant before closing.
What does this most likely indicate, and what should happen?
Module 4 · The Nucleus Family Tree: From CI22 to CI600
A report lists the patient's device as a 'CI532'.
What does that tell you?
Module 5 · Choosing a Nucleus Array: Perimodiolar vs Lateral Wall
A trainee is puzzled that an ~18 mm Slim Modiolar reaches a similar angular depth to an ~25 mm Slim Straight.
Why?
Module 6 · Advanced Bionics: 16 Current Sources and Current Steering
A device rep states the implant gives 120 channels via current steering.
What is the accurate clinical picture?
Module 7 · The HiFocus Array Family and Naida Processors
An older record mentions a HiFocus array placed with a separate Silastic 'positioner'.
Why was the positioner withdrawn?
Module 8 · The MED-EL Philosophy: Long, Flexible, Lateral-Wall
A learner counts 24 contacts on a MED-EL array and assumes 24 independent channels.
What is correct?
Module 9 · SYNCHRONY, FSP and the SONNET/RONDO System
A SYNCHRONY recipient needs a 3 T MRI of the brain.
What feature helps?
Module 10 · The Electrode Array as a Frequency Ruler
A new recipient says voices sound high-pitched and 'cartoonish'.
What is the device-level explanation?
Module 11 · Why 22 Electrodes Behave Like 8 Channels
A family asks whether a 22-electrode implant hears better than a 16-electrode one.
What does the evidence show?
Module 12 · The Three Array Families: Lateral-Wall, Perimodiolar, Mid-Scala
A surgeon weighs a perimodiolar versus a lateral-wall array for a patient with useful residual hearing.
Which consideration dominates?
Module 13 · Stimulation Modes: From Monopolar to Tripolar
To reduce channel interaction, a clinician considers tripolar instead of monopolar stimulation.
What is the trade-off?
Module 14 · Dynamic Range and Electrode-to-Neuron Distance
A learner is surprised that the gap between threshold and comfort is only ~15 current units.
What is the implication?
Module 15 · Materials, Reliability and MRI
A centre wants to compare two implants' reliability fairly.
Which metric is the standard?
Module 16 · Electric-Acoustic Stimulation and Hearing Preservation
A candidate has normal low-frequency hearing but a steep high-frequency loss.
What device strategy fits?
Module 17 · Special Arrays for the Difficult Cochlea
Imaging shows a common-cavity malformation with no modiolus.
Which array is appropriate?
Module 18 · The Wider World: Other Manufacturers and the Pioneers' Electrodes
A 9-year-old implanted overseas presents for follow-up. Her parents bring a processor you do not recognise; records say her implant is a Nurotron Venus with a 24-electrode array. Her mapping is overdue and a part is broken.
What is the most appropriate next step?
Module 20 · The Cochlear Implant of the Future and Choosing a Device
A colleague asks which array is simply the best.
What is the honest answer?
Module 1 · The Lineage at a Glance: Why Coding Strategies Keep Changing
An engineering trainee claims that 'a cochlear implant with 22 electrodes always delivers 22 independent channels of information.' Their mentor pushes back, pointing to decades of comparative data.
What is the best correction to the trainee's claim?
Module 2 · One Electrode, One Sound: The Single-Channel Era
A historian reviewing CI records finds that a 1984-era single-channel recipient could detect when someone was speaking and use it to support lip-reading, but scored near zero on open-set word lists in quiet.
Which engineering limitation best explains this performance pattern?
Module 3 · Compressed Analog: The First Multichannel Waveform Strategy
A 1980s Ineraid recipient on a compressed-analog processor reports that speech sounds 'muddy' and that increasing the level makes high-frequency consonants worse rather than clearer.
Which CA-specific mechanism best explains the worsening high-frequency percept with level?
Module 4 · Continuous Interleaved Sampling: The Pulse That Changed Everything
An audiology student programs a research CIS map with a 400 Hz envelope low-pass cutoff but only a 250 pps stimulation rate per channel, then is puzzled that the voice pitch sounds distorted.
What is the engineering problem with this configuration?
Module 5 · Tracking the Voice: F0/F2 Formant Extraction
A 1980s Nucleus recipient on an F0/F2 processor identifies many vowels by their pitch and openness but struggles badly with consonants such as /s/, /f/ and /th/.
Which design limitation of F0/F2 best accounts for the poor consonant perception?
Module 6 · Adding F1: The F0/F1/F2 Processor
An engineer upgrades a recipient from an F0/F2 to an F0/F1/F2 processor. Vowel identification improves clearly, but consonant scores barely move.
What does this pattern reveal about the F0/F1/F2 strategy?
Module 7 · Multipeak (MPEAK): Formants Plus High-Frequency Bands
Two recipients are compared in quiet and in noise. On MPEAK both do well in quiet, but in cafeteria noise one drops sharply while a third recipient on a spectral-maxima strategy holds up better.
What is the most likely reason MPEAK degrades more in noise?
Module 8 · SMSP: Letting the Spectrum Choose
A research processor in the early 1990s analyses speech with sixteen band-pass filters but stimulates only six electrodes at a time, choosing them anew every few milliseconds, and never tries to label any peak as a formant.
Which strategy is being described, and what is its defining advantage over MPEAK?
Module 9 · The n-of-m Family: SPEAK and the Rise of Peak Picking
A clinician notes that a Nucleus 22 SPEAK user has good speech-in-quiet but reports that music and voice pitch sound rough, and the research team attributes this to the strategy's timing.
Which SPEAK characteristic best explains the rough pitch percept?
Module 10 · ACE: Spectral Maxima Meet High Rate
A newly implanted Nucleus-24 adult is fitted with ACE at 900 pps selecting 10 of 22 bands. The clinician is asked how ACE differs from the SPEAK strategy the clinic used a decade earlier.
What is the most accurate description of the ACE-versus-SPEAK difference?
Module 11 · Chasing Fine Structure: FSP, FS4 and the Temporal-Pitch Ceiling
A bilingual Mandarin-speaking recipient is switched from an envelope-only strategy to FS4 and reports that lexical tones and music sound somewhat clearer, but tone discrimination still falls short of a normal-hearing peer.
Which factor best explains why FS4 helps but does not fully restore tone perception?
Module 12 · Virtual Channels: Current Steering and Current Focusing
An Advanced Bionics user on HiRes Fidelity 120 can reliably tell apart pitches steered to virtual positions between electrodes on a lab task, yet a clinical trial finds no clear group advantage of F120 over conventional HiRes for speech.
How is this apparent contradiction best reconciled?
Module 13 · The Present Commercial Landscape: Four Makers, Five Philosophies
A device-selection committee notes that across MED-EL, Cochlear, Advanced Bionics and Oticon Medical, large head-to-head trials show no clearly superior strategy for average speech-in-quiet outcomes, despite very different coding philosophies.
What is the best engineering explanation for this convergence in outcomes?
Module 14 · The Frontier: Deep Learning, Closed Loops and Light
A research group proposes replacing a CI's entire front-end, filter bank, peak-picker and mapping stages with a single neural network trained to output stimulation patterns directly from raw audio, but worries the model is too large for an ear-level processor.
Which approach best addresses both the design goal and the size constraint?
Module 1 · From Decision to Theatre: What Preparation Must Achieve
A 4-year-old boy with congenital profound bilateral sensorineural hearing loss is judged an audiological candidate for cochlear implantation, and the family is keen to proceed quickly. The work-up is incomplete: recent viral upper-respiratory illnesses, an unfinished pneumococcal vaccination course, no ECG recorded, and imaging showing a wide vestibular aqueduct. The parents ask why everything cannot simply be done on the day of the operation.
Which element of pre-operative preparation most directly reduces the risk of a life-threatening complication, and how should it be timed?
Module 2 · Fit for Surgery: The Medical and Anaesthetic Work-up
A 2-year-old boy with congenital profound bilateral sensorineural hearing loss is listed for cochlear implantation. His mother mentions that his older sister had two unexplained fainting spells during play, and that a maternal cousin died suddenly in childhood. The child is otherwise well, fully immunised for his age, with normal development apart from deafness. The CT and MRI show normal cochlear anatomy. The surgical team is reviewing his work-up before booking theatre.
Which pre-operative investigation is most important to obtain before this child proceeds to anaesthesia, and why?
Module 3 · Vaccination and Meningitis Prophylaxis
A 2-year-old with a Mondini malformation completed PCV13 and Hib but never PPSV23, scheduled for implantation in three weeks.
Most appropriate vaccination action?
Module 4 · The Multidisciplinary Sign-off and the Final Plan
A 4-year-old boy with congenital profound bilateral sensorineural hearing loss is presented at the cochlear implant case conference. Audiology confirms he meets candidacy criteria; the surgeon has reviewed his CT/MRI, which shows a normal cochlea on the right and an enlarged (wide) vestibular aqueduct on the left. The speech-language therapist and teacher of the deaf report a committed, engaged family. The nurse notes his pneumococcal and Hib vaccinations were completed 4 weeks ago. The anaesthetic record is complete except that no ECG has been performed. The team is about to confirm the ear and sign him off for theatre.
Which item should halt sign-off until it is addressed?
Module 5 · Counselling and Shared Decision-Making
A 58-year-old accountant with a 6-year history of progressive bilateral sensorineural hearing loss is referred for cochlear implantation after his best-aided speech scores fell below candidacy thresholds. He tells the team he expects the implant to 'restore my hearing to normal so I can go back to conference calls and concerts straight away.' He lives alone, scores high on a screening depression inventory, and has not met any implant users. He asks to proceed 'as soon as possible.'
Which counselling action should the team prioritise before scheduling surgery?
Module 6 · Informed Consent: Risks, Benefits and Alternatives
A 58-year-old woman with post-lingual progressive hearing loss has measurable low-frequency residual hearing in the ear proposed for implantation. She uses a hearing aid that no longer gives her useful speech understanding. During your consent discussion she says, 'So the implant will fix my hearing, and if I don't like it I'll just go back to my hearing aid.' She has not yet received her pneumococcal vaccination, and surgery is provisionally booked for 10 days from now.
Which two points are the most important to correct or address before this patient can give valid informed consent?
Module 7 · Preparing the Family and the Home
A 14-month-old boy with bilateral profound congenital sensorineural hearing loss is scheduled for cochlear implantation. His parents, who have normal hearing, are still visibly distressed by the diagnosis. They tell the team they expect the implant to fix his hearing so he will simply start talking on time, and they have not yet decided whether to pursue spoken language, sign, or both. They live two hours from the centre, both work full time, and have not arranged any early-intervention or speech-language therapy. The surgeon is satisfied with candidacy and anatomy, but the implant coordinator pauses the pathway to address family readiness before confirming a surgical date.
Which pre-operative action will most improve this child's long-term communication outcome?
Module 8 · What an Implant Can and Cannot Do
A 61-year-old man with bilateral severe-to-profound sensorineural hearing loss of 4 years' duration, post-lingually deafened and a regular but now-failing hearing aid user, attends pre-operative counselling for a unilateral cochlear implant. He tells the team he is looking forward to hearing normally again and to enjoying orchestral music as he did before, and asks how soon after the switch-on he will understand conversation like it used to be. He lives alone and works in a noisy open-plan office.
What is the most appropriate counselling response to set realistic expectations?
Module 9 · Why Outcomes Vary: The Predictors Behind Expectations
A 61-year-old man is referred for cochlear implant assessment. He has bilateral profound sensorineural hearing loss. History reveals he lost useful hearing in his left ear gradually from his mid-twenties (now effectively deaf for 35 years on that side) but only declined to profound loss in his right ear over the past 4 years, during which he has worn a hearing aid daily and still scores 30 percent on aided sentence testing in that ear. Imaging shows normal cochlear anatomy bilaterally and no ossification. He tells the team he expects the implant to restore normal hearing so he can return to playing in his amateur string quartet.
Which combination of factors makes the RIGHT ear the appropriate side to implant, and what is the single most important counselling point to address?
Module 10 · Realistic Expectations by Group
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Module 11 · Measuring Expectations and Psychological Readiness
A 61-year-old post-lingually deafened accountant is referred for cochlear implant evaluation. He has used hearing aids for 15 years with declining benefit and tells the team he expects the implant to let him hear perfectly again, especially in restaurant meetings. On the CIQOL-Expectations instrument his anticipated scores are near-maximal across all six domains. His Beck Depression Inventory score is in the moderate range, and he reports low mood and social withdrawal over two years. Audiology and imaging confirm he is an excellent surgical candidate.
Which finding most strongly warrants targeted pre-operative intervention before proceeding, and why?
Module 12 · Pre-habilitation and Patient Education
A 4-year-old with delayed work-up; parents expect immediate normal hearing at switch-on and have not chosen a communication mode.
Most important pre-habilitation action before activation?
Module 13 · Bringing It Together: The Preparation Checklist
A 4-year-old boy with congenital profound bilateral sensorineural hearing loss is scheduled for unilateral cochlear implantation in two weeks. The coordinating nurse is completing the pre-theatre checklist. Medical clearance, CT and MRI (showing normal cochlear anatomy), psychological/family-readiness assessment and signed consent are all documented. However, the vaccination record shows only that PCV was administered yesterday; PPSV23 has not yet been given. A 12-lead ECG performed at the candidacy visit was normal.
Which single item on the checklist should prompt the team to reconsider whether surgery can safely proceed as scheduled?
Module 1 · The Operation in Context: What Implant Surgery Must Achieve
A fit 54-year-old man with post-lingual profound bilateral hearing loss is booked for unilateral implantation. He asks how long he will be in hospital and what the surgeon's single most important intraoperative priority is once the array is at the cochlea.
Which intraoperative principle most directly protects his long-term outcome at the moment of array insertion?
Module 2 · Surgical Anatomy of the Temporal Bone
During a posterior tympanotomy in an adult the trainee has opened the recess but cannot confidently identify the round window, and several air cells nearby look like possible openings. The attending asks how to confirm the correct target.
What anatomical rule best confirms the round window's location here?
Module 3 · Medical Fitness and Anaesthesia for Surgery
A 3-year-old with congenital profound deafness is scheduled for implantation. The anaesthetist asks the surgeon to confirm two things: which preoperative test is mandatory in this child, and whether a long-acting muscle relaxant may be used to ensure stillness.
What is the correct combined answer?
Module 4 · The Incision and the Receiver Bed
A 34-year-old is referred for re-implantation of a failed device. The original surgery, done elsewhere as a child, used a large curved C-shaped post-auricular flap, and the scar is still visible. You are planning your incision.
What is the most appropriate incision choice for this revision?
Module 5 · Mastoidectomy and the Facial Recess Approach
Three weeks after an uncomplicated cochlear implantation through a standard facial recess approach, a patient develops a House-Brackmann grade II facial weakness that was not present immediately post-op. Drilling notes record the recess was opened with limited irrigation and a thin bony cover over the nerve was preserved.
What is the most likely mechanism of this delayed facial nerve dysfunction?
Module 6 · Surgical Approaches Compared: Recess, Suprameatal and Beyond
A 14-month-old with bilateral profound sensorineural loss is scheduled for simultaneous bilateral cochlear implantation. Preoperative CT shows an underdeveloped mastoid, a narrow facial recess, and an anteriorly displaced facial nerve on the right; the middle-fossa dura sits at a normal height bilaterally.
Which approach best addresses this child's anatomy while limiting facial-nerve risk and total drill time?
Module 7 · Reaching the Scala Tympani: Round Window vs Cochleostomy
Intra-operatively a surgeon cannot clearly see the round-window membrane through the facial recess. To save time they drill a cochleostomy on the promontory well anterior and slightly superior to where they expect the window, and advance the array. Post-operative imaging and poor early performance suggest a scala-vestibuli insertion.
Which choice most likely caused the array to enter the wrong scala?
Module 8 · Atraumatic Electrode Insertion: The Soft-Surgery Principles
During implantation of a perimodiolar array, the surgeon advances the electrode and feels rising resistance two-thirds of the way in. The trainee suggests pushing firmly to seat it fully.
What is the most appropriate next step consistent with soft-surgery principles?
Module 9 · Hearing-Preservation Surgery and EAS
A 54-year-old has a steeply sloping loss: thresholds of 35 dB HL at 250 Hz and 40 dB HL at 500 Hz but over 90 dB HL above 1500 Hz, with CNC word scores of 28% in the best-aided condition. He is counselled about EAS.
Which combination of choices best protects his residual low-frequency hearing?
Module 10 · Securing the Receiver-Stimulator
An 11-month-old is being implanted; intraoperatively the lateral skull is measured at only 2.5 mm thick over the planned well site. The trainee proposes drilling a standard 3 mm bony seat.
What is the safest fixation approach here?
Module 11 · The Ossified Cochlea
A 4-year-old is referred 6 weeks after pneumococcal meningitis with bilateral profound hearing loss. CT shows a faint bead of new bone in the proximal basal turn of the right scala tympani and a uniformly sclerotic left cochlea; MRI confirms loss of fluid signal on the left but a preserved cochlear nerve bilaterally.
What is the most appropriate next step?
Module 12 · Malformed Cochleae and the CSF Gusher
A 2-year-old with congenital deafness has CT showing a single ovoid cavity replacing the cochlea and vestibule, with a wide internal auditory canal. As the surgeon opens the cavity, clear fluid wells up briskly and obscures the field.
Which combination best manages this situation?
Module 13 · Intraoperative Monitoring and Verification
After a smooth-feeling full insertion in a 3-year-old, impedances are all normal, AutoNRT thresholds are robust on every tested electrode, and the surgeon is satisfied. The circulating nurse asks whether the intraoperative radiograph is still needed.
What is the correct response?
Module 14 · Revision and Reimplantation Surgery
A 9-year-old, implanted at age 2, is brought in after a fall at football. He has become withdrawn and his teacher reports his listening has switched off intermittently. The audiologist finds fluctuating performance and occasional reports of a buzzing shock, but the manufacturer's remote integrity test is entirely normal and impedances are within range.
How should this presentation be classified and managed?
Module 15 · Minimally Invasive, Image-Guided and Robotic Surgery
A 58-year-old with substantial low-frequency residual hearing is counselled for an electric-acoustic (EAS) implant. The surgeon is determined to minimise insertion trauma and asks whether a robotic insertion tool would help, and what evidence supports it.
What is the best evidence-based statement to give this patient about robotic-assisted electrode insertion?
Module 16 · Postoperative Care and the Road to Switch-On
Three days after a straightforward implant, an adult is brought back by family with a tense, fluctuant swelling over the receiver site, mild discomfort, but no fever and an intact, non-erythematous incision. The external processor has not yet been fitted.
What is the most likely problem and the appropriate first response?
Module 1 · The Watchful Operation: Why We Monitor and Preserve
A trainee asks why so much equipment is wheeled in for a routine adult cochlear implant when the operation looks like a straightforward mastoidectomy and insertion. The consultant points out that, unlike the trainee, the surgeon cannot see inside the cochlea and cannot ask the sleeping patient anything.
What is the single best justification for intraoperative monitoring during cochlear implantation?
Module 2 · Guarding the Face: Intraoperative Facial-Nerve Monitoring
During a paediatric implant in a child with CHARGE syndrome, the surgeon drilling the facial recess hears a sudden burst from the facial-nerve monitor that becomes a continuous train as the burr advances. Preoperative CT had shown an inferiorly displaced facial nerve.
What is the most appropriate immediate response to this monitor finding?
Module 3 · Is the Device Working? Intraoperative Impedance and Integrity
At the end of an otherwise smooth adult implant, intraoperative telemetry shows one apical contact reading a strikingly high, out-of-range impedance while every neighbouring contact sits in a tight low-impedance band. The integrity test of the internal device passes normally.
What does this single high-impedance contact most likely represent, and what is the implication?
Module 4 · Listening to the Nerve: Intraoperative ECAP/NRT
A 14-month-old with congenital profound deafness and no behavioural responses is undergoing implantation. After full insertion the array shows normal impedances, but the surgeon wants objective confirmation that stimulating the device actually activates the auditory nerve before the family is counselled.
Which intraoperative measure most directly confirms that the auditory nerve responds to electrical stimulation through the implant?
Module 5 · Reflex and Brainstem: Intraoperative ESRT and eABR
A 3-year-old with a hypoplastic cochlear nerve on MRI is in theatre for a cochlear implant. The team needs objective evidence on the table that electrical stimulation reaches the brainstem before committing to the cochlear implant rather than referring for an auditory brainstem implant.
Which intraoperative measure best confirms that stimulation propagates up to the brainstem and informs the CI-versus-ABI decision?
Module 6 · Catching the Fold-Over: Intraoperative Imaging and Field Telemetry
During implantation with a pre-curved slim modiolar array, insertion felt slightly resistant near the end. The surgeon wants to confirm the array is fully and correctly spiralled before closing, but the centre wants to minimise radiation and theatre time.
Which intraoperative tool can detect a tip fold-over fastest and without ionising radiation, before wound closure?
Module 7 · Where Is the Array? Verifying Electrode Position
A surgeon completes a smooth full insertion of a pre-curved perimodiolar array. Impedances are normal and ECAP responses are present across the array. Routine intraoperative cone-beam CT shows the apical-most electrodes doubled back, with the tip pointing basally.
What is the most appropriate next step?
Module 8 · Why Save the Hearing You Have
A 58-year-old has near-normal hearing at 250-500 Hz but a precipitous loss above 1.5 kHz. With well-fitted hearing aids his word understanding in quiet is only 40%, and conversation in restaurants is impossible. He asks whether anything other than 'just stronger hearing aids' can help.
What is the most appropriate option to discuss?
Module 9 · How the Cochlea Gets Hurt: Mechanisms of Insertion Trauma
A patient implanted with a hearing-preservation protocol has excellent preserved low-frequency thresholds at activation. Postoperative imaging shows a full scala-tympani insertion with no translocation. Over the next eight weeks his low-frequency hearing steadily declines and impedances rise.
Which mechanism best explains this course?
Module 10 · Soft Surgery: The Atraumatic Technique
A surgeon implanting a 45-year-old with 35 dB HL low-frequency residual hearing has drilled a cochleostomy and opened the endosteum. The field is oozing and a thin film of bone dust is visible at the entry. An assistant reaches in with a fine sucker to clear the perilymph and improve the view.
What is the single most important correction to protect residual hearing at this moment?
Module 11 · The Gentle Electrode: Atraumatic Array Design
A 28-year-old has a steeply sloping loss with serviceable hearing up to 500 Hz, normal cochlear anatomy and a measured cochlear duct length at the longer end of normal. The team wants to preserve low-frequency hearing for electric-acoustic stimulation.
Which electrode strategy best fits this preservation goal?
Module 12 · Protecting the Cochlea with Drugs
A surgeon performs a round-window hearing-preservation implantation and, during insertion, encounters unexpected resistance and a more difficult-than-planned advancement. The patient has worthwhile low-frequency residual hearing the team is trying to save.
Which pharmacological measure has the best-supported rationale to protect residual hearing in this scenario?
Module 13 · Listening as You Insert: Real-Time Electrocochleography
During a hearing-preservation cochlear implant insertion you are monitoring real-time electrocochleography through the apical electrode. The cochlear microphonic has been stable at about 90% of its baseline amplitude. At an insertion depth of roughly 18 mm the CM abruptly falls to 55% and stays there as you continue to advance gently.
What is the most appropriate immediate response to this finding?
Module 14 · Counting What Is Saved: Measuring Hearing Preservation
Two cochlear-implant studies both report 'excellent hearing preservation.' Study A defines preservation as any measurable residual threshold at 250 Hz one month after surgery. Study B uses the HEARRING classification at 12 months and reports the proportion with complete plus partial preservation, and separately the proportion with functional hearing usable for electric-acoustic stimulation.
Why are Study B's figures more useful for comparing electrode arrays and counselling patients about EAS?
Module 15 · What Preserved Hearing Buys, and Where This Is Going
A 58-year-old with good low-frequency hearing but a severe-to-profound high-frequency loss is implanted with hearing preservation in mind. Insertion is monitored with real-time ECochG, the array is placed atraumatically, and at activation she has excellent preserved low-frequency thresholds and is fitted with electric-acoustic stimulation. She reports markedly better understanding in restaurants and that music sounds natural again. Six months later her low-frequency thresholds have deteriorated and the acoustic component is no longer helpful.
What is the most appropriate next step?
Module 1 · What Programming Achieves
A 58-year-old man returns three days after his switch-on, frustrated, saying voices sound robotic and tinny and he is convinced the implant has failed. His incision is clean and his day-1 map gave consistent audibility across the speech range.
What is the most appropriate response?
Module 2 · Anatomy of the MAP: Thresholds, Comfort and Dynamic Range
A Nucleus recipient's basal high-frequency electrodes show a dynamic range of only 12 clinical units, while her apical electrodes sit comfortably at 45. She reports high-pitched sounds are harsh and quickly become uncomfortable.
What is the most reasonable programming approach for the narrow-range basal electrodes?
Module 3 · The First Switch-On
At switch-on a 46-year-old woman with long-standing deafness reports the programming beeps blend with her tinnitus, so she cannot tell when she is truly hearing the signal. Her T-level responses look erratic and possibly suprathreshold.
Which technique best helps obtain valid threshold responses?
Module 4 · Setting Threshold (T) Levels
Three weeks after activation, an adult Nucleus recipient reports a constant bacon-frying or static hiss in quiet rooms and says soft sounds seem unnaturally present, but speech in conversation is clear. Soundfield warbled-tone thresholds are better than 25 dB HL across the speech range.
What is the most likely programming cause, and what is the appropriate first adjustment?
Module 5 · Setting Comfort Levels and Loudness Balancing
An adult recipient understands speech reasonably in quiet but complains that the program is harsh and tiring and that one region of sound jumps out. On sweeping at the C level, electrode 14 is clearly louder than its neighbours, and overall the patient keeps the processor volume turned down.
What is the best programming response?
Module 6 · Frequency Allocation and the Filter Map
An adult upgrading from a legacy Nucleus processor to a current device complains that, with the default allocation, voices sound unnaturally high-pitched and wrong, even though objective measures and stimulation levels are fine. Speech scores have dropped since the upgrade.
What is the most appropriate frequency-allocation step?
Module 7 · Strategy, Rate and Maxima in the Clinic
A 58-year-old new Nucleus recipient does well in quiet but reports that running speech sounds thin and lacks detail. She is on the ACE default of 8 maxima at 900 pulses per second with normal impedances and comfortable C levels. She asks whether a faster, more powerful program would help.
What is the most evidence-aligned next adjustment?
Module 8 · Front-End Processing: IDR, Sensitivity and Noise
A high-performing adult recipient does well one-to-one but struggles badly in restaurants. He uses a single everyday program with an omnidirectional microphone, a 60 dB input dynamic range, default sensitivity, and no noise reduction enabled. He is reluctant to carry accessories.
Which front-end change is the best first step for his restaurant difficulty?
Module 9 · Programming the Young Child
A 13-month-old is being activated. He cannot give reliable behavioural feedback, and the programming stimulus needed to elicit a stapedial reflex is clearly too loud for him today. The clinician has obtained ECAP (NRT) thresholds across the array intraoperatively.
What is the most appropriate approach to setting this child's first map?
Module 10 · Objective Measures at the Fitting
A 3-year-old returns for her first MAP after activation. She will not condition for play audiometry and tympanometry shows patent pressure-equalisation tubes bilaterally. Impedances are normal. The audiologist needs a defensible starting profile for T and especially C.
Which objective approach is most appropriate for setting the upper-stimulation profile in this child?
Module 11 · Troubleshooting the MAP
A woman with otosclerosis returns three weeks after activation reporting cheek twitching whenever the room is noisy. The twitch is reproducible on the four most basal contacts at her C level; impedances are all normal and her word scores are otherwise improving.
What is the most appropriate first step?
Module 12 · The Poor Performer: A Systematic Work-up
A 9-year-old implanted at age 2 has plateaued and recently regressed on word testing. Impedances are normal, the integrity test is OK, and datalogging confirms full-time use. The audiologist has reprogrammed three times in two months without lasting benefit.
What is the most appropriate next step?
Module 13 · Bimodal and Bilateral Fitting
A 6-year-old with bilateral flat profound hearing loss (both ears near 95 dB HL) has used a unilateral implant for two years with excellent open-set speech but cannot localise sound and struggles in his noisy classroom. The family asks whether a hearing aid on the other ear would help.
What is the most appropriate recommendation for the contralateral ear?
Module 14 · EAS and Special Maps
A new EAS recipient with a steeply sloping loss (250 to 500 Hz near 35 dB HL, dropping below 80 dB HL by 1500 Hz) hears well electrically but reports that voices sound thin and pitch-shifted, and music is unpleasant. The acoustic component is currently off.
What is the most appropriate first step?
Module 15 · Longitudinal Care, Datalogging and Verification
A 4-year-old returns six weeks after activation. The caregiver reports he often ignores soft speech. Datalogging shows 11 hours of daily use across varied environments. Aided sound-field thresholds are 40 dB HL at 250 and 500 Hz; the microphone cover is intact and clean.
What is the most appropriate next step?
Module 1 · What We Mean by Outcomes
A 58-year-old postlingually deafened man is reviewed one year after implantation. He repeats only 58% of CNC monosyllabic words in the booth and is disappointed, having expected a near-perfect score. On AzBio sentences in quiet he scores 88%, he is back to using the telephone with familiar callers, and his wife reports he no longer asks for repetitions at home.
What is the most appropriate interpretation of this result?
Module 2 · The Outcome Test Battery
An audiologist evaluating a candidate finds the patient scores 96% on HINT sentences in quiet, comfortably above the 60% candidacy threshold, yet the patient reports being unable to follow conversation in any group setting. The audiologist wants a measure that better reflects this difficulty.
Which change to the test battery is most appropriate?
Module 3 · The Adult Learning Curve
A 62-year-old postlingually deafened woman is seen two weeks after activation. Her CNC word score is only 22% and she is anxious that the implant has failed. Her duration of deafness was four years and she wore hearing aids consistently beforehand. Her device map gives aided detection thresholds of 28 dB HL across the frequencies tested.
What is the most appropriate counselling and plan?
Module 4 · The Variability Problem
Two postlingually deafened adults are implanted on the same day at the same centre with identical devices, processors and coding strategies. Both have excellent surgery with full electrode insertion. At twelve months, one scores 82% CNC words and the other 18%. The second patient asks why, since everything was the same.
What is the most accurate explanation to give this patient?
Module 5 · Duration of Deafness and Age
A 58-year-old man developed bilateral severe-to-profound sensorineural hearing loss following meningitis at age 30 and has used hearing aids with declining benefit since. He stopped using the telephone about 26 years ago. His spoken language was fully established before his loss. He meets audiometric criteria for implantation and asks about his likely result.
Which feature of this history most strongly tempers the expected outcome?
Module 6 · The Ear and the Nerve: Peripheral Predictors
A child is referred with a profound unilateral loss. High-resolution MRI shows a markedly small cochlear nerve in the affected ear, and CT shows a narrowed internal auditory canal, although the cochlea is well formed. The family asks whether a cochlear implant in that ear will give the same result as in a child with normal anatomy.
What is the most accurate counselling point regarding the peripheral substrate here?
Module 7 · Cognition and the Listening Brain
A 74-year-old man with long-standing post-lingual deafness is implanted. His electrode placement and impedances are ideal and his map is well-balanced, yet at three months his word scores trail those of a 40-year-old implanted the same week. On testing he shows slowed processing speed and reports that following conversation in his daughter's busy kitchen leaves him exhausted within minutes.
What best explains his slower progress and high listening effort despite an excellent device fit?
Module 8 · Paediatric Outcomes: Language, Literacy and School
Two congenitally deaf children attend the same clinic. One was identified by newborn screening and implanted at 10 months; the other was identified late and implanted at 3 years. Both have well-fitted devices and engaged families. The parents of the later-implanted child ask whether their daughter will catch up to the first child and to hearing classmates.
Based on CDaCI-era evidence, what is the most accurate counselling?
Module 9 · Speech and Language Development in Children
A boy implanted at 14 months is reviewed at age 5. His parents speak to him constantly, he attends a listening-and-spoken-language preschool, and unfamiliar adults understand almost all of what he says. A girl in the same clinic, implanted at 13 months with an equally good device, is harder to understand and has a smaller vocabulary; her family rarely engages her in extended conversation and she has weak working memory on testing.
What best accounts for the gap between these two similarly and early-implanted children?
Module 10 · Hearing in Noise and in Space
A 58-year-old unilateral implant user scores 92 percent on CNC words in a quiet booth and is delighted. At his annual review he complains he cannot follow anything at family dinners and twice failed to hear a car approaching from his deaf side. His clinician repeats sentence testing in spatially separated babble.
Which finding best explains the mismatch between his quiet-booth success and his real-world difficulty?
Module 11 · Music and the Human Voice
A 34-year-old violinist with a single implant, fitted two years ago, scores 88 percent on sentences in quiet and is thrilled with conversation. She returns distressed: she can keep time with an ensemble and clap rhythms perfectly, but says melodies sound flat and the same, she can no longer tell a violin from a viola, and music has lost its pleasure.
Which explanation best fits this pattern of preserved and lost musical abilities?
Module 12 · Two Ears Are Better: Bilateral, Bimodal and SSD Outcomes
A 42-year-old develops sudden profound deafness in the right ear after a viral illness; the left ear is normal. Six months on she cannot tell where sounds come from, struggles in meetings when colleagues sit on her deaf side, and has a constant intrusive right-sided tinnitus. Her hearing aid trial in the deaf ear gave nothing because the loss is too severe.
Which intervention is most likely to restore localisation and improve speech in noise while also addressing her tinnitus?
Module 13 · Patient-Reported Outcomes
A 58-year-old postlingual recipient returns at 12 months with a CNC word score of 72% in quiet, comfortably within the expected range. She is nonetheless unhappy: she avoids restaurants, cannot tell which child is calling her across the garden, and finds an evening of conversation exhausting. You decide to capture the problem with a structured self-report tool before adjusting her plan.
Which instrument is best suited to characterise the specific complaints she is describing?
Module 14 · Outcomes in Special Groups
A 4-year-old with a confirmed diagnosis of auditory neuropathy spectrum disorder is referred for implantation. Behavioural responses are inconsistent and otoacoustic emissions are present but the auditory brainstem response is absent. The family wants to know what speech outcome to expect. MRI is requested before counselling is finalised.
Which single finding most changes the expected speech-perception outcome and therefore the counselling?
Module 15 · Predicting and Benchmarking Outcomes
A 62-year-old postlingual recipient with a 6-year duration of deafness and good preoperative residual hearing was counselled that he had favourable predictors. At 9 months his CNC word score is 28%, well below the expected band for someone with his profile, and his SSQ scores are correspondingly low. The map looks stable and he reports wearing the device all day.
What is the most appropriate response to this below-benchmark result?
Module 1 · Why Rehabilitation Matters
A second-grade teacher tells the implant team, five weeks after switch-on, that the cochlear implant 'isn't working' because her newly implanted pupil still does not understand what she says in class.
What is the most accurate explanation for the teacher's observation?
Module 2 · The Rehabilitation Team and Pathway
An audiologist programming a newly implanted adult repeatedly hears that the recipient confuses similar-sounding consonants and is too anxious to use the telephone again after years of struggling with hearing aids.
Which combined team response best addresses this situation?
Module 3 · Plasticity and the Window of Opportunity
Two congenitally deaf children are referred. One receives a cochlear implant at 18 months; the other, lost to follow-up, is first implanted at 8 years of age. Both have well-placed arrays and good detection thresholds.
What best predicts the likely difference in their spoken-language outcomes?
Module 4 · The Principles of Auditory Training
A newly switched-on adult recipient scores 0% on open-set sentence recognition in the sound booth and is discouraged, saying speech sounds like noise. The audiologist wants to begin auditory training that gives early success while still building toward real-world listening.
What is the most appropriate first training condition?
Module 5 · Auditory-Verbal Therapy
Hearing parents of a 14-month-old with bilateral profound hearing loss, newly implanted, tell the team their goal is for their child to speak and attend a mainstream school. They ask the audiologist who will deliver the listening therapy and what their own role will be.
Which arrangement best reflects an auditory-verbal approach?
Module 6 · Family-Centred Early Intervention
A two-year-old has worn a cochlear implant for six months but is making slow language progress. The clinic discovers the device is often left off at home, the television runs constantly, and the busy single parent feels uncertain about what to do between visits.
Which action best reflects family-centred early intervention?
Module 7 · Developing Spoken Language in Children
A boy is activated at 26 months after profound congenital deafness. At his 6-month post-activation review (chronological age 32 months) the family is distressed that he is producing only canonical babble and a handful of single words while his hearing cousins of the same age speak in sentences. The implant is mapped well and he wears it all waking hours.
What is the most appropriate way to frame his progress and set the next therapy goal?
Module 8 · Speech Production and Articulation
A 5-year-old implanted at 18 months has good open-set word recognition and clear vowels, but listeners outside the family often misunderstand her. Assessment shows she omits final /s/ and /t/, substitutes stops for fricatives, and speaks in a relatively flat, monotone voice.
Which therapy focus is most likely to improve her overall intelligibility soonest?
Module 9 · Adult Aural Rehabilitation
A 64-year-old retired teacher with 8 years of progressive deafness is implanted and activated. At 6 weeks she is frustrated: speech sounds 'robotic,' she cannot use the phone, and she lives alone with little daily conversation. She was given the device and a follow-up map appointment but no structured rehabilitation plan.
What is the most appropriate next step to improve her outcome?
Module 10 · Communication Strategies and Repair
A 58-year-old engineer, six weeks post-activation, reports good one-to-one conversation at home but dreads team meetings, where he nods along without understanding and is exhausted afterwards. His audition-alone scores in clinic are good. He says he never tells colleagues about his implant because he does not want to seem incapable.
Which intervention most directly targets his meeting difficulty?
Module 11 · Training for Noise and the Real World
A 34-year-old teacher, four months post-activation, has excellent scores in quiet clinic testing but says she still cannot follow her students in a noisy classroom and avoids staff-room conversations. She owns a remote microphone the clinic dispensed but leaves it in a drawer because no one showed her how it fits into her day.
What is the most appropriate next step in her rehabilitation?
Module 12 · Music Rehabilitation
A 47-year-old former amateur guitarist, one year post-implant with good speech scores, is despondent that music 'sounds like noise' and has stopped listening entirely. He has aidable low-frequency hearing in the non-implanted ear that he no longer uses. He wants to know whether music will ever come back.
What combination best addresses his music goals?
Module 13 · Technology and Telepractice in Rehabilitation
A 2-year-old, six weeks after activation, lives four hours from the implant centre. The family attended initial in-person sessions but cannot sustain weekly travel. The clinic offers a video link in which the speech-language therapist guides the mother through listening play at home, plus a gamified listening app for daily practice.
What is the clinician's primary role in this telepractice model?
Module 14 · School Transition and Educational Support
A 6-year-old with a unilateral implant has just started mainstream Year 1. She scores well on quiet booth speech testing but her teacher reports she 'switches off' in group activities and mishears instructions across the busy classroom. The room has hard floors and a noisy ventilation unit.
What is the single most effective first intervention for her classroom listening difficulty?
Module 15 · Measuring Progress and Steering Therapy
A 3-year-old implanted at 14 months has steadily climbed the IT-MAIS and CAP over two years. At the latest review the parents report no gain for several months, and the teacher of the deaf notes she seems to mishear more in class. Her last booth scores, six months ago, were good.
What is the most appropriate first step in responding to this apparent stall?
Module 1 · Beyond the Audiogram: Why Outcomes and Value Matter
A man reviewed after implantation.
Which measures answer both questions?
Module 2 · What Is Quality of Life, and How Do You Put a Number on It?
A 58-year-old man with postlingual profound bilateral sensorineural hearing loss is assessed before unilateral cochlear implantation. As part of an audit, the clinic records his pre-operative health utility on a Health Utilities Index Mark III questionnaire as 0.50, and notes he could also be asked a VAS, time trade-off, or standard gamble question.
On the scale used to express his score of 0.50, what do the anchors 0 and 1.0 represent, and what does 0.50 imply?
Module 3 · The Generic Yardsticks: HUI3, EQ-5D and Utility
A commissioner asks your CI programme to justify funding. Forty adult postlingual recipients show only a small, non-significant EQ-5D change, yet describe dramatically better telephone use and confidence, and their NCIQ scores rose sharply. The commissioner questions cost-effectiveness given the flat EQ-5D.
How should you interpret the flat EQ-5D against the clear NCIQ and patient-reported gains?
Module 4 · Hearing Through the Patient's Ears: Disease-Specific Instruments
A 58-year-old postlingually deafened woman is reviewed 18 months after unilateral cochlear implantation. Her open-set sentence scores have risen from 0% preoperatively to 76%, yet she tells your audiologist she still struggles to know who is speaking at a dinner table and finds noisy restaurants exhausting. Your department wants to document her quality-of-life change for a service-evaluation report and is debating which questionnaire to administer. The generic EQ-5D completed at her last visit showed almost no change.
Which instrument set would best capture both her overall implant-related quality of life and the specific spatial-hearing and listening-effort difficulties she describes?
Module 5 · Does It Help? Quality-of-Life Gains in Adults
A 71-year-old retired schoolteacher with a 6-year history of progressive bilateral sensorineural hearing loss, now profoundly deaf, has withdrawn from her book club and family dinners and screens positive for depression. She spoke normally until her hearing failed in her sixties. Her aided open-set sentence score is 12%. She worries she is too old for an implant.
Which counseling statement is best supported by the quality-of-life and cost-utility evidence?
Module 6 · The Child and the Family: Quality of Life in Pediatric Implantation
An 18-month-old boy with congenital profound bilateral sensorineural hearing loss is referred for cochlear implantation. His parents, both hearing, are still visibly grieving the diagnosis; the mother screens positive for moderate depression on a routine questionnaire and says she feels she 'failed' her son. They ask the surgeon to promise that the implant will make him 'normal' and let him go to the local mainstream school. The team must counsel them about expected outcomes and quality of life.
Which counselling and management approach best reflects the evidence on pediatric and family quality of life?
Module 7 · The Economist's Toolkit: QALYs, ICERs and Thresholds
A health ministry in a middle-income country weighs a paediatric cochlear implant programme. Economists present lifetime direct costs of device, surgery and maintenance, discounted at 5% per year, divided by an estimated lifetime utility gain. The base-case ICER is $28,000 per QALY from a health-system perspective; GDP per capita is $4,500. One advisor says it fails the WHO benchmark; another says the analysis ignores children who will attend mainstream rather than special schools.
Which single change is most likely to move this programme from not cost-effective to cost-effective, and why?
Module 8 · Counting the Costs: A Lifetime of an Implant
A national health authority asks you to model the lifetime cost of implanting a 2-year-old congenitally deaf child versus continued amplification with special-education support. The model includes device and surgery, the inpatient stay, two years of intensive mapping and rehabilitation, then recurring batteries, accessories, annual reviews and a processor upgrade every several years, plus a small revision probability. A junior analyst proposes entering every cost at face value in the year it occurs and dividing the undiscounted total by the QALYs gained.
What is the single most important methodological correction before comparing this model against the authority's cost-per-QALY threshold?
Module 9 · Was It Worth It? Cost-Effectiveness in Adults
A 58-year-old man has had progressive bilateral postlingual sensorineural hearing loss over 12 years and now scores 8% on aided open-set sentence testing. His regional health authority asks your team to justify funding a unilateral cochlear implant on cost-effectiveness grounds before approving the procedure.
Which single figure best supports funding by reference to the published adult cost-utility literature, and why is this patient a favorable case?
Module 10 · The Strongest Case: Cost-Effectiveness in Children
V.
Q?
Module 11 · The Second Ear and the Hard Cases
A 58-year-old woman has used a single cochlear implant for three years with excellent open-set speech understanding and is delighted with her result. She now asks her surgeon and her health system to fund a second implant for the other, still-deaf ear, citing difficulty localising sound at busy family gatherings. Separately, the same clinic is reviewing two other funding requests that week: a 70-year-old man with bilateral profound deafness seeking his first implant, and a 45-year-old man with normal hearing on one side and sudden total deafness on the other (single-sided deafness).
Applying incremental cost-effectiveness reasoning, how should the team expect these three requests to compare on cost per QALY, and why?
Module 12 · Value Beyond the Clinic: Education, Work and Society
A regional health authority deciding whether to fund a pediatric cochlear implant programme receives two appraisals of the same programme. From a strict health-system perspective, counting only device, surgery, rehabilitation and maintenance, the cost-utility ratio is about $9,000 per QALY. From a societal perspective, additionally crediting reduced special-education expenditure as implanted children move from residential placements (up to $142,000 per year) toward mainstream classrooms, the ratio is markedly lower and in one scenario shows a net saving. The committee, used to $20,000-$50,000 per QALY thresholds, asks why the numbers differ and which to believe.
What best explains the difference between the two appraisals?
Module 13 · Worth It for Whom? Access, Equity and the Global Picture
A health ministry in a lower-middle-income country (GDP per capita ~$2,200) asks your unit to advise on funding a national cochlear-implant programme. A vendor quotes $35,000 per device-and-surgery package. Your team's local cost-utility model returns about $14,000 per QALY for unilateral implantation in postlingually deaf adults, a figure your colleague proudly notes is better than the $20,000-$50,000 threshold the textbooks use. The minister, however, points to the WHO-CHOICE framework her economists apply to every other programme.
Why does the unilateral implant programme fail to clear the cost-effectiveness bar in this country despite a cost-utility ratio that looks favourable by high-income standards, and what single change would most defensibly bring it within threshold?
Module 1 · Who Are the Special Populations?
A 58-year-old salesman has normal hearing in the right ear and a profound sensorineural loss in the left after a sudden idiopathic event 8 months ago. He fails every bilateral candidacy criterion you usually apply, but is severely bothered by left-sided tinnitus and can no longer follow conversations in his noisy showroom.
What is the most appropriate framing of his candidacy?
Module 2 · Single-Sided Deafness and Asymmetric Loss
A 7-month-old infant fails newborn screening on the right with confirmed profound sensorineural loss and has normal left-ear hearing. The family asks about a cochlear implant for the right ear to give their child two working ears.
What is the single most important next investigation before considering implantation?
Module 3 · Auditory Neuropathy Spectrum Disorder
A 14-month-old child passed the OAE-based newborn screen but the parents report inconsistent responses to sound and delayed babbling. Repeat testing shows robust otoacoustic emissions and a present cochlear microphonic, but the auditory brainstem response is absent. Behavioural thresholds suggest only a moderate loss.
What best explains this picture and the correct next step?
Module 4 · Cochlear Nerve Deficiency
A 14-month-old with congenital profound right-sided deafness and normal left hearing is referred for implant evaluation. CT shows a narrow right bony cochlear nerve canal measuring 1.1 mm. The family asks whether the right ear can be implanted to restore two-sided hearing.
What is the most appropriate next step before committing to implantation of the right ear?
Module 5 · Malformed Inner Ears: Candidacy and Expectations
A 3-year-old with bilateral profound deafness has a CT reported as Mondini malformation with 1.5 cochlear turns and an enlarged vestibular aqueduct. The parents have read online that 'a malformed cochlea cannot be implanted' and arrive expecting bad news.
What is the most accurate counselling for this family?
Module 6 · Post-Meningitic Deafness and the Ossified Cochlea
A 2-year-old develops bilateral profound deafness six weeks after pneumococcal meningitis. MRI shows reduced fluid signal in the basal turn of the right cochlea and a patent left cochlea. The family is told the local clinic has a three-month surgical waiting list.
What is the most appropriate management priority?
Module 7 · Otosclerosis, Meniere's and the Diseased Ear
A 58-year-old woman with a long history of progressive bilateral hearing loss has no measurable air conduction and unrecordable bone conduction; CT shows confluent lucency throughout both otic capsules. She is implanted and hears well, but at switch-on several basal electrodes produce visible facial twitching at comfortable loudness levels.
What is the most appropriate first step to manage the facial twitching?
Module 8 · The Very Young Infant
A 10-month-old fails newborn screening and serial ABR confirms a bilateral profound sensorineural loss with no responses; a three-month trial of well-fitted hearing aids shows no detectable benefit. The parents ask whether their child is too young for an implant.
What is the most appropriate response regarding candidacy?
Module 9 · The Older Adult and Cognition
An 84-year-old man with severe-to-profound bilateral sensorineural loss gets little benefit from hearing aids. He is socially withdrawn and his family reports recent memory complaints. He is otherwise medically well and keen to proceed. His referring physician asks whether he is too old and whether the memory concerns rule him out.
What is the most appropriate counselling and decision?
Module 10 · Children with Additional Disabilities
A 3-year-old with severe-to-profound bilateral hearing loss, spastic diplegic cerebral palsy and a non-verbal IQ estimate around 65 has worn well-fitted hearing aids consistently but shows only inconsistent sound detection and no emerging words. The family asks whether an implant will let him talk.
What is the most appropriate framing of candidacy and goals for this child?
Module 11 · Syndromic Deafness
A 14-month-old with profound congenital deafness is referred for implantation. The family mentions that an older sibling died suddenly during a febrile illness, and that the child has had two unexplained fainting-like episodes.
What is the single most important step before scheduling surgery?
Module 12 · Prelingual Adolescents and Adults
A 19-year-old, deaf since birth, was raised orally, has worn bilateral hearing aids consistently and gets some benefit from lip-reading plus amplification. He is highly motivated, asks specifically for help hearing in his college classes, and understands he may never use the phone.
How should the team counsel and proceed?
Module 13 · The Only-Hearing Ear and the Medically Complex Patient
A 9-year-old with profound congenital deafness is referred for cochlear implantation. The child has had two unexplained syncopal episodes during running play, and an older sibling died suddenly in childhood.
What is the most important next step before proceeding to surgery?
Module 14 · When the Cochlea or Nerve Cannot Be Used: ABI Candidates
A 4-year-old with bilateral cochlear nerve aplasia on MRI has had no response to a trial cochlear implant in one ear, with no auditory percepts on activation. The family asks whether any hearing is still possible.
What is the most appropriate next option to provide auditory access?
Module 15 · Special Populations in Low-Resource Settings
A charity offers to donate 50 cochlear implant devices to a district hospital in a low-income region that currently has one ENT surgeon, no audiologist, no speech therapist, and no newborn hearing screening.
What is the most important determinant of whether these donated devices will produce durable hearing outcomes?
Module 1 · When the Cochlea Is Built Differently
A 3-year-old with profound bilateral deafness is referred for implantation. CT shows a strikingly malformed, dilated cochlea with no normal modiolus. The parents are told the cochlea 'looks very abnormal' and that an implant is therefore impossible.
What single additional piece of information most directly determines whether this child can receive a cochlear implant?
Module 2 · How the Inner Ear Is Made — and Mis-Made
A radiologist describes a child's cochlea as having a normal external size and coil but an absent modiolus and missing interscalar septa, giving a 'cystic' apex. The basal turn is well formed.
What does this combination of findings tell you about the timing of the developmental arrest?
Module 3 · Naming the Malformations: Jackler, Sennaroğlu and Grover
Two surgeons review the same CT. One labels the ear a 'cochlear hypoplasia'; the other calls it a 'common cavity variant'. Both are experienced and confident.
What does this disagreement most likely illustrate about the classical classifications?
Module 4 · The Empty Promontory: Michel Aplasia and the Rudimentary Otocyst
A profoundly deaf 2-year-old with no response to any amplification has a CT showing a flat promontory with no identifiable cochlea, vestibule, or semicircular canals on either side. MRI shows narrow internal auditory canals with no demonstrable cochlear nerves.
What is the most appropriate next step regarding auditory rehabilitation?
Module 5 · Too Little Cochlea: Aplasia and Hypoplasia
An 18-month-old with profound bilateral hearing loss has CT showing a small bud-like cochlea continuous with a present, slightly enlarged vestibule on each side. MRI shows a present but thin cochlear nerve bilaterally and a partially formed modiolus.
What is the most appropriate management of the hearing loss?
Module 6 · One Chamber for Everything: The Common Cavity
A 3-year-old with congenital profound deafness has CT showing a single ovoid cavity replacing both the cochlea and vestibule, with no internal partition and no modiolus. A cochlear nerve is present on MRI. The surgeon notes the facial nerve appears to run anomalously over the cavity.
Which surgical strategy best fits this anatomy?
Module 7 · The Incomplete Partitions: IP-I, IP-II and IP-III
A 4-year-old boy with profound bilateral mixed hearing loss is referred after a previous attempt at stapes surgery elsewhere produced a torrential fluid leak. CT shows a cochlea with retained interscalar septa but a completely absent modiolus, the basal turn sitting directly against a bulbous internal auditory canal. Genetic testing identifies a POU3F4 mutation.
Which incomplete-partition type is this, and what is the dominant intraoperative concern at cochlear implantation?
Module 8 · The Enlarged Vestibular Aqueduct
A 9-year-old has worn hearing aids for low-frequency mixed loss since toddlerhood. Her thresholds have dropped twice in stair-step fashion, each time within days of a playground fall, and aided speech understanding is now poor. CT shows a vestibular aqueduct measuring 2.4 mm at the operculum with an otherwise well-formed cochlea; tympanometry is normal.
What is the most likely explanation for her apparent conductive component, and what is the cochlear-implant outlook?
Module 9 · The Decider: The Cochlear Nerve and Its Bony Canal
A 2-year-old with congenital profound deafness has a normal-appearing cochlea on CT, but the bony cochlear nerve canal measures 1.0 mm and the internal auditory canal looks narrow. A parasagittal oblique T2 MRI shows the facial nerve clearly but no identifiable nerve in the antero-inferior position of the canal.
What does the imaging indicate, and how should the device decision be framed?
Module 10 · Reading the Malformed Ear: CT and MRI
A 2-year-old with profound congenital deafness has an HRCT showing a cochlea with 1.5 turns, a confluent apical turn and an enlarged vestibular aqueduct measuring 2.1 mm at its midpoint. The referring centre asks whether imaging is complete.
What is the single most important imaging step still required before finalising candidacy?
Module 11 · The Genes Behind the Shapes
A 4-year-old boy has bilateral mixed hearing loss. CT shows an absent modiolus and a wide channel between the internal auditory canal and the cochlear basal turn bilaterally, with stapes fixation. A maternal uncle is also deaf.
Which gene is the most likely cause, and what does it predict for surgery?
Module 12 · In the Operating Room: Gusher, Facial Nerve and the Difficult Insertion
During cochlear implantation in a child whose CT showed IP-III (absent modiolus, wide IAC-cochlea channel), opening the cochleostomy produces a brisk pulsatile flow of clear fluid that does not settle with suction.
What is the most appropriate immediate management?
Module 13 · Choosing the Array, Setting Expectations: Electrodes and Outcomes
A 3-year-old with bilateral profound SNHL has CT/MRI showing a Mondini deformity (IP-II) with a normal-calibre cochlear aperture and a clearly present cochlear nerve. The modiolus is partially deficient.
Which array choice and counselling message best fit this child?
Module 14 · A Prognosis-Oriented Algorithm for Decision-Making
A 4-year-old in a tertiary CI programme has severe-to-profound SNHL. Imaging shows a useful cochlear lumen, a normal cochlear aperture and a present cochlear nerve, with an interscalar septal defect and an absent modiolus - an IP-III (X-linked) pattern.
Stepping through the prognosis-oriented algorithm, what does this child's branch predict?
Module 15 · From Diagnosis to Decision: Putting It All Together
A 2-year-old has unilateral EVA with fluctuating, currently moderate-to-severe hearing that drops after minor head knocks. The cochlear lumen and nerve are normal. The family asks whether she needs an implant now.
Which destination on the pathway best fits her today?
Module 1 · Why Two Ears Are Better Than One
A 58-year-old man with an excellent right-side cochlear implant scores 92% on monosyllables in a quiet booth but says he is 'wiped out' after work meetings and never knows who is speaking around a conference table.
Which limitation of single-ear listening best explains his complaints despite his high booth scores?
Module 2 · The Cues the Brain Uses: ITD, ILD and Spatial Hearing
A bilateral cochlear implant user can tell whether a sound is on her left or right but performs near chance when asked to fine-tune its exact angle, and gets little extra benefit when noise and speech come from different sides.
Which binaural cue is she most likely able to use, and which is she missing?
Module 3 · The Three Binaural Benefits: Head Shadow, Summation and Squelch
A new bilateral cochlear implant recipient is thrilled that conversation in a noisy restaurant is easier when the talker sits opposite and the clatter is to one side, but reports almost no improvement when everyone speaks from the same direction as the noise.
Which binaural benefit explains his restaurant improvement, and why is it limited when speech and noise are colocated?
Module 4 · Finding the Sound: Localization With Two Devices
A 58-year-old sequential bilateral CI user returns 6 months after activation of her second implant. In the sound booth she now points to loudspeakers with an RMS error of about 24 degrees, down from roughly 52 degrees when tested with only her first implant. She reports she can finally tell which direction her grandchildren are calling from. She still occasionally turns the wrong way for sounds directly behind her.
Which mechanism best explains the large improvement in her horizontal localization with the second implant?
Module 5 · Speech in Noise: The Real Payoff
A bilateral CI user is tested with sentences at a fixed SNR. With speech from the front and a single noise source at 90 degrees to the right, he scores far better using both implants than using only his left implant. When the same total noise is instead presented diffusely from loudspeakers all around him, the advantage of using both implants shrinks to almost nothing.
What best explains why his bilateral advantage was large with a single lateral noise source but small in diffuse noise?
Module 6 · Beyond the Booth: Real-World and Quality-of-Life Benefits
A bilateral CI user's booth results are only modestly better with two implants than one: localization improved from near-chance to about 26 degrees, and her separated-noise SRT improved by roughly 3 dB. On the SSQ her Spatial subscale rose markedly while her Speech and Qualities scores rose only a little. She tells you she would 'never go back to one ear' because conversations in noisy family gatherings are far less exhausting.
How should you interpret the apparent mismatch between her modest booth gains and her strong preference for two implants?
Module 7 · One Surgery or Two: Simultaneous vs Sequential Implantation
A 14-month-old with bilateral profound congenital deafness is referred for cochlear implantation. The family asks whether both ears should be done in one operation or one at a time.
What is the preferred strategy and the main reason?
Module 8 · Mind the Gap: The Inter-Implant Interval
A child implanted in the right ear at age 2 returns at age 9 for consideration of a left (second) implant. The parents ask whether the long delay means the second ear is now useless.
What is the most accurate counselling?
Module 9 · Two Ears for a Developing Brain: Bilateral CI in Children
Parents of a 12-month-old with bilateral profound deafness ask why their audiologist recommends two implants rather than starting with one and 'seeing how she does'.
What is the strongest rationale for early bilateral implantation here?
Module 10 · The Second Ear in Adults: Evidence and Candidacy
A 54-year-old teacher with bilateral profound postlingual deafness has used a right cochlear implant for two years with excellent speech scores in quiet. She struggles in her noisy classroom and cannot tell which student is speaking. Her left ear has been profoundly deaf for three years. She asks whether a second implant is worth it.
What is the most accurate counselling statement about adding a left cochlear implant?
Module 11 · Best of Both Worlds: Bimodal Hearing (CI + Hearing Aid)
A 60-year-old man has a left cochlear implant and continues to wear his right hearing aid, which fits a moderate low-frequency hearing loss sloping to profound in the highs. He reports that voices on the phone (implant ear) sound clear but flat, while music and recognizing his wife's voice across a noisy room feel better when he keeps the right hearing aid in.
What best explains why he prefers wearing both devices?
Module 12 · Making Two Different Ears Work Together: Bimodal Fitting
A bimodal user reports that since her recent hearing-aid adjustment, sounds seem to pull entirely to her hearing-aid side and her speech-in-noise scores have dropped below what she achieves with the implant alone. Her implant map is stable and well-balanced.
What is the most appropriate first step?
Module 13 · The Missing Timing: Why Two Implants Aren't Two Normal Ears
A bilaterally implanted adult, deafened post-lingually, localizes a ringing phone to the correct side of the room but cannot pick her grandson's voice out of dinner-table chatter the way she expected. On testing, ILD-based localization is good but her interaural-time-difference threshold is ~480 microseconds.
Which engineering fact best explains why she localizes by side yet lacks the fine binaural 'squelch' she hoped for?
Module 14 · Choosing the Strategy: Bilateral, Bimodal or Wait
A 4-year-old with congenital bilateral profound loss has used one CI well for 18 months. He has no measurable aidable hearing in the other ear. His parents ask whether they should add a hearing aid, get a second implant, or wait until he is older.
What is the most appropriate recommendation, and why?
Module 15 · Worth the Second Ear? Cost, Access and the Binaural Future
A health-system commissioner with a fixed budget must decide between funding second implants for 50 existing adult unilateral users or funding first implants for 50 currently unimplanted adults on the waiting list.
From a population health-economics standpoint, which choice generally yields more quality-adjusted life-years, and why?
Module 1 · Why Implanting the Cochlea Touches Balance
A 54-year-old with progressive bilateral sensorineural hearing loss is counseled before unilateral cochlear implantation. He asks whether the operation could affect his balance.
What is the most accurate statement about vestibular risk from cochlear implantation?
Module 2 · Anatomy and Physiology of the Balance Organs
A student asks why a person with one completely destroyed labyrinth can walk normally in daylight but staggers in a dark bathroom.
Which principle best explains this?
Module 3 · How Implant Surgery Injures the Labyrinth
A trainee proposes that post-implant vertigo must mean the surgeon physically tore the vestibule during insertion.
What is the better-supported mechanism of vestibular injury in most cases?
Module 4 · Who Already Has Vestibular Loss: Etiology and Baseline
A child became deaf after bacterial meningitis and is referred for implantation. The team debates whether vestibular testing is worthwhile given the urgency.
What does the etiology predict about this child's vestibular status?
Module 5 · Reading the Dizzy History and the Five-Minute Screen
A candidate reports spontaneous spinning lasting about an hour at a time, accompanied by a roaring tinnitus, fullness and fluctuating hearing in one ear.
Which etiology does this symptom-timing pattern most suggest?
Module 6 · The Vestibular Audiogram I: Canal Tests Across Frequency
A candidate has an absent caloric response on one side but a normal vHIT gain for the horizontal canal on the same side.
How should this discordance be interpreted?
Module 7 · The Vestibular Audiogram II: VEMP, Otoliths and Function Tests
A candidate has a normal vHIT in all three canals but you want to know the saccular status before choosing which ear to implant.
Which test directly assesses saccular function?
Module 8 · The Dizzy Patient After Implantation
Six weeks after implantation a patient develops recurrent spells of spinning lasting up to two hours with new aural fullness and tinnitus on the implanted side.
What does this delayed pattern most suggest?
Module 9 · Choosing the Ear: Vestibular Risk and Bilateral Implants
A candidate has a profoundly hypofunctional right labyrinth and a normally functioning left labyrinth. Both ears are audiologically suitable for a single implant.
Which ear should generally be implanted, and why?
Module 10 · Atraumatic Surgery: Preserving Hearing and Balance Together
A surgeon wants to minimize both residual-hearing loss and post-operative dizziness in a candidate with useful low-frequency hearing.
Which combination of choices best serves both goals?
Module 11 · The Child's Balance and Motor Development
A neurologically normal 20-month-old, deaf from birth, is referred for implantation and has not yet walked independently.
What does the motor history most likely indicate?
Module 12 · Falls and the Older Recipient
A 72-year-old reports persistent unsteadiness for several weeks after implantation, but examination shows no nystagmus and no new measurable vestibular deficit.
What is the most appropriate management?
Module 13 · The Vestibular and Cochleovestibular Implant Frontier
During placement of a vestibular-implant electrode in the horizontal-canal ampulla, stimulation produces a brisk pure horizontal nystagmus.
What does this intraoperative finding indicate?
Module 1 · The Complication Landscape: Classifying What Can Go Wrong
Six weeks after implantation a 4-year-old has a 5 mm area of incisional separation at the upper edge of the scar with no exposed device. It is dressed, kept clean, and the processor is rested; it heals fully in ten days with no further surgery.
Using the standard functional definition, how should this event be classified?
Module 2 · The Wound and the Flap: Skin, Healing and Breakdown
A 58-year-old smoker with type 2 diabetes returns three months after implantation with a dusky, thinning patch of skin directly over the magnet. There is no fluid and no exposed device, but the skin blanches poorly and is tender.
What is the most appropriate first step?
Module 3 · Infection and the Implant: From Pocket Infection to Biofilm
An adult develops redness and a discharging sinus over the receiver four months post-implant. Swabs grow MRSA. After two weeks of culture-directed antibiotics and surgical debridement the wound improves, but within days of stopping antibiotics the discharge and swelling return.
What does the prompt relapse after stopping antibiotics most strongly suggest?
Module 4 · In the Operating Room: Intraoperative Complications
A 3-year-old with an enlarged vestibular aqueduct and an incomplete-partition cochlea is undergoing implantation. The instant the surgeon opens the cochleostomy, clear fluid pours out under pressure and obscures the field.
What is the most appropriate immediate management?
Module 5 · Wrong Place, Wrong Path: Electrode Misplacement and Migration
A patient implanted with a precurved perimodiolar array has unexpectedly poor word scores at activation. Telemetry shows abnormal impedances apically, and the spread-of-excitation profile from the most apical contacts is reversed. A conebeam CT shows the apical electrodes lying basal to the mid-array contacts.
What is the most likely problem?
Module 6 · When the Device Fails: Hard and Soft Failure
A long-term CI user reports a steady decline in clarity over six months plus occasional sharp shocks. Telemetry communicates normally and the manufacturer's integrity test is normal. Mapping, electrode impedances and a medical work-up reveal no explanation, and reprogramming does not help.
How is this best classified, and what is the implication?
Module 7 · The Twitch: Facial-Nerve Stimulation
A 58-year-old woman implanted three years ago for far-advanced otosclerosis returns reporting a new left-eyelid twitch every time she listens, worse with loud sounds. At the booth, stimulating her three most basal electrodes reproduces a visible facial twitch; the apical electrodes do not.
What is the most appropriate first management step?
Module 8 · Beyond Sound: Non-Auditory Percepts and Pain
A cochlear-implant user reports a sharp, needle-like pain in the ear only when the second-most-basal electrode is active; the rest of the array sounds normal. Impedance telemetry shows that single electrode reads markedly out of range compared with its neighbours.
What does this pattern most suggest, and what is the appropriate next step?
Module 9 · The Dizzy Recipient: Vestibular Symptoms After Implantation
A 70-year-old man is six weeks post cochlear implantation. His initial postoperative unsteadiness resolved within a week, but he now reports brief spinning episodes lasting under a minute, triggered only when he rolls over in bed or looks up. Hearing through the implant is good.
What is the most likely diagnosis and the most appropriate management?
Module 10 · The Poor Performer: A Structured Workup
A 58-year-old, 4 years post-implant, had stable CNC word scores around 70% for 3 years. Over 6 weeks her scores fell to 35% and she reports intermittent 'popping.' External parts have been swapped with no change. The device still locks and the integrity test is normal.
What is the single best next step?
Module 11 · Listening to the Device: Objective Measures in Troubleshooting
At a troubleshooting visit, electrodes 1 and 2 (most apical) show very high, unmeasurable impedance. The integrity test is normal and ECAP is robust on the remaining channels. The recipient had a full insertion documented intraoperatively but now reports a thin, tinny sound.
What does the impedance pattern most likely indicate?
Module 12 · Seeing the Problem: Imaging the Implanted Ear
Intraoperatively, after inserting a precurved slim modiolar array, the surgeon obtains a portable modified-Stenvers radiograph. The most apical contacts appear to loop back and overlap rather than continuing the smooth spiral.
What is the finding and the appropriate action?
Module 13 · Going Back In: Revision and Reimplantation
An 11-year-old, implanted at age 3, presents with progressive deterioration in speech scores and intermittent facial twitching on the implant side. Integrity testing is normal and impedances are unremarkable; reprogramming and a processor swap do not help.
How should this situation be classified and managed?
Module 14 · Living With the Device: MRI, Magnets and External Hazards
A 60-year-old cochlear implant user is scheduled for an abdominal hernia repair. The anaesthetic and surgical teams ask the CI programme how to handle electrocautery and whether the implant is a problem for the operation.
What is the key intraoperative instruction regarding diathermy?
Module 15 · Children, Prevention and Building a Safer Programme
A 4-year-old implanted at age 2 presents with a high fever, neck stiffness and reduced consciousness. The parents recall the child had a cold and ear pain over the preceding days.
What is the most important immediate consideration, and what preventive measure most reduces this risk in implanted children?
Module 1 · The Frontier: What Still Needs Solving
A motivated adult implant user scores 82 percent on sentences in a quiet room but tells you she still cannot follow conversation in a restaurant and finds music harsh and tuneless. Her device is programmed correctly and all 22 electrodes are active.
What single limitation best explains why her quiet-room score is good but her music and noise performance are poor?
Module 2 · The Steady Hand: Robotics-Assisted Electrode Insertion
You are implanting a 58-year-old with substantial residual low-frequency hearing and want to preserve it. You can insert the lateral-wall array by hand in under a minute, or mount a motorised insertion tool set to 0.2 mm per second, which will take several minutes.
What is the main rationale for choosing the slow motorised insertion in this specific patient?
Module 3 · A Keyhole to the Cochlea: Image-Guided and Minimally Invasive Surgery
A team proposes a percutaneous, image-guided cochlear implantation for a candidate. On the planning CT, the only straight trajectory that reaches the round window passes within a fraction of a millimetre of the facial nerve, and the facial recess is narrow.
What is the single most important safeguard before and during drilling along this trajectory?
Module 4 · The Pharmacological Electrode: Drug-Eluting and Bioactive Arrays
A 58-year-old undergoes implantation with a hearing-preservation electrode and good low-frequency thresholds pre-op. At activation, basal impedances are normal. Over the next 3 months her low-frequency residual hearing declines and basal-electrode impedances climb steadily. Her surgeon is reviewing whether a different array might have helped.
Which mechanism best explains the parallel rise in impedance and loss of residual hearing, and what array strategy is designed to counter it?
Module 5 · More Contacts, Less Trauma: Next-Generation Arrays
A manufacturer markets a new array with 44 micro-fabricated contacts, double the count of its previous device, and claims it will 'double spectral resolution.' A clinician on the advisory board is asked whether the claim is biologically plausible for typical recipients using monopolar stimulation.
What is the strongest scientific objection to the 'double the contacts, double the resolution' claim?
Module 6 · Closing the Gap: The Electrode-Neuron Interface
Two adult users have identical, well-positioned 22-contact arrays. One scores 85% on sentences in quiet; the other scores 45% and struggles badly in noise despite extensive programming. Imaging shows good electrode position in both. The audiologist suspects the difference lies at the electrode-neuron interface rather than in the device or fitting.
What single concept best explains why two physically identical, well-placed arrays can yield such different outcomes, and what programming approach follows from it?
Module 7 · Nothing on the Outside: The Totally Implantable Implant
A 34-year-old competitive swimmer with bilateral profound hearing loss asks whether she can get an implant with 'nothing on the outside' so she can hear in the pool and while sleeping. She has read about a totally implantable device.
What is the most accurate counselling statement?
Module 8 · The Microphone Under the Skin and the Power to Run It
An engineer designing a totally implantable cochlear implant reports that the prototype works in the lab but, once implanted in a model, the user's own chewing and voice swamp the speech signal, and high frequencies sound muffled.
Which sensing change most directly addresses these specific complaints?
Module 9 · A Smarter Processor: AI and Sound Processing
A CI recipient reports that a new deep-learning noise-reduction setting makes restaurant conversation noticeably easier, but is disappointed it still does not sound like 'normal hearing' and asks why a smarter processor cannot just fix everything.
What is the best explanation?
Module 10 · Care at a Distance: Remote Programming and Self-Fitting
A stable adult CI user lives 400 km from the implant centre. Her last three annual maps were essentially unchanged. She has a smartphone-paired processor with data-logging and a Remote Check app, and good home internet.
Which model of follow-up is best supported for this recipient?
Module 11 · Regrowing the Ear: Hair-Cell and Neural Regeneration
The parents of a profoundly deaf 2-year-old have read that scientists can 'regrow hair cells' and ask whether they should wait for regeneration rather than proceed with implantation now.
What is the most accurate and responsible counsel?
Module 12 · A Genetic Cure: Gene Therapy Restoring Hearing
A 14-month-old has profound bilateral hearing loss. Genetic testing returns biallelic pathogenic OTOF variants. CT and MRI show a normally formed cochlea and a present cochlear nerve. The parents ask whether anything other than an implant is possible.
What is the most accurate counsel given current evidence?
Module 13 · Hearing in Light: The Optical Cochlear Implant
A motivated, well-informed adult with profound deafness reads about a light-based cochlear implant that promises far more frequency channels and asks whether she should wait for it instead of accepting a conventional electrical implant now.
What is the most accurate counselling statement?
Module 14 · The Self-Tuning Implant: Closed-Loop Fitting
A CI programme serving a rural region with very few audiologists asks how technology could reduce the number of in-person fitting visits each recipient needs, especially for the young children on their list.
Which combination best reflects what can genuinely reduce expert-fitting burden today?
Module 15 · The Bionic Ear: Putting It Together
At a global health planning meeting, a funder is excited by optogenetics and gene therapy and proposes directing the bulk of a hearing-health budget toward bringing these to a tertiary centre, in a country where most deaf children currently receive no implant at all.
What is the most defensible response?
Module 1 · Why Music Is the Implant's Hardest Sound
A 58-year-old postlingually deafened engineer, six months after implantation, scores 88% on open-set sentences in quiet and uses the telephone daily. At review she is distressed that she cannot recognise her favourite folk songs and finds the radio 'just noise with a beat'.
What best explains why her speech is excellent while her music perception is poor?
Module 2 · The Building Blocks: Pitch, Timbre and Rhythm
A musician asks you to explain, before her implant is activated, what parts of music she should expect to hear. She wants to know which acoustic features carry melody, which carry the identity of her cello, and which carry the beat.
Which acoustic dimension primarily lets a listener tell a cello from a flute playing the same note?
Module 3 · What the Implant Keeps and What It Throws Away
A recipient with a 22-electrode array tells you he can clap accurately to the beat of any song and follow a drum line, but every melody 'sounds the same' and he cannot tell a guitar from a piano. His engineer asks why so many electrodes give so little melody.
What best explains the gap between his good rhythm and his poor melody and timbre?
Module 4 · The Hardest Part: Pitch and Melody
A 54-year-old post-lingually deafened CI user, six months after activation, reports she can 'feel' songs and clap along perfectly, and recognises 'Happy Birthday' instantly - yet when her therapist plays familiar tunes on a keyboard with every note the same length, she cannot name a single one and her guesses are random.
What best explains the dissociation between her preserved song recognition and her failure on the equal-duration melody test?
Module 5 · Which Instrument Is That? Timbre Perception
A 12-year-old experienced CI user tells his audiologist he can always tell when a piano is playing and 'kind of' tell a drum, but in his school orchestra recordings 'all the smooth ones sound the same' and the violins 'sound scratchy and angry.' He still enjoys music overall.
Which explanation best accounts for his pattern of preserved and impaired instrument perception?
Module 6 · Rhythm: The One That Survives
A rehabilitation therapist planning a new CI user's music programme is deciding where to begin. The recipient is discouraged after failing a pitch-matching exercise and says 'maybe music just isn't for me anymore.' The therapist wants an early win that builds on what the implant does best.
Which activity is most likely to give this recipient early, motivating success?
Module 7 · Many Notes at Once: Harmony and Polyphony
A 58-year-old post-lingually deafened CI user, six months after activation, reports that he can follow and enjoy a solo singer-songwriter recording and tap along to dance music, but a symphony 'sounds like noise' and he can no longer tell whether a chord is major or minor.
Which single factor best explains the pattern of preserved and lost musical abilities he describes?
Module 8 · Putting a Number on It: Measuring Music Perception
Two CI users are tested in clinic. Patient A scores 85% on CAMP melody identification but rates recorded music only 3/10 for pleasantness and rarely listens. Patient B scores just 40% on the same melody test yet rates music 8/10 and listens daily.
What does this contrast most clearly demonstrate?
Module 9 · Can Better Coding Help? Strategies and Music
A keen amateur musician, two years post-implant on a standard ACE program, asks whether switching to a fine-structure strategy will 'fix' music for her. She has no usable acoustic hearing in either ear.
What is the most accurate counselling response?
Module 10 · Out of Tune: Frequency-to-Place Mismatch
A 58-year-old post-lingually deafened CI user with a shallow array scores 92% on sentences in quiet and is delighted with speech. Three months on, she reports that familiar songs are recognisable but 'everything sounds a few notes too high and slightly sour,' especially the harmony in a choir.
What best explains her experience?
Module 11 · Growing Up Musical: Children and the Implant
Parents of a 6-year-old implanted at 12 months ask whether it is 'worth' enrolling her in music classes, since they have read that implants convey pitch poorly. She already loves singing along to songs and dances to the beat.
What is the most appropriate counselling?
Module 12 · Rescuing the Melody: Bimodal and Electric-Acoustic Hearing
A 45-year-old woman with a unilateral implant has excellent speech understanding but finds music 'flat and metallic.' She has aidable low-frequency hearing in her non-implanted ear but currently wears no hearing aid on that side.
Which intervention is most likely to improve her music perception?
Module 13 · Training the Musical Ear: Rehabilitation
A 54-year-old, six months post-implant, says she understands speech well but 'music sounds like noise' and she has stopped listening. She asks whether anything can be done.
What is the most evidence-supported recommendation?
Module 14 · Enjoyment, Identity and Quality of Life
A 30-year-old keen amateur singer is distressed one year post-implant: on testing she identifies melodies poorly, yet she says she still loves putting on her old favourite albums and singing along. She asks if her implant has 'failed' for music.
What is the most appropriate counselling response?
Module 15 · Toward a Musical Implant: The Future
A 40-year-old musician with high-frequency hearing loss but useful low-frequency residual hearing is being counselled about a cochlear implant and asks specifically how to maximise future music enjoyment.
Which strategy is the most evidence-supported NEAR-TERM lever for better musical hearing in this candidate?
Module 1 · Beyond Hearing: The Implant's Other Two Jobs
A 58-year-old man with profound bilateral hearing loss is being counselled for a cochlear implant. He says, almost in passing, that the constant high-pitched ringing keeps him awake more than the deafness ever did, and asks whether the implant will help.
What is the most accurate thing to tell him about the implant's effect on his tinnitus?
Module 2 · The Ringing in Silence: Tinnitus in the Deafened Ear
A 45-year-old woman with profound sudden sensorineural hearing loss in one ear is overwhelmed by a loud ringing on that side. Her surgeon proposes implanting that ear partly to address the tinnitus. A colleague worries that, because the ear is dead, the ringing must come from the ear and so the brain cannot be the source.
How should the central-gain model answer the colleague's worry?
Module 3 · How the Implant Quietens the Ringing
A patient implanted for single-sided deafness reports that her tinnitus is almost gone whenever the processor is on, and that for about half an hour after she takes it off at night the side stays unusually quiet before the ringing slowly creeps back.
Which mechanisms best explain this on-versus-off pattern?
Module 4 · What the Evidence Shows: Tinnitus Outcomes
A 58-year-old man with bilateral severe-to-profound loss and constant, bothersome tinnitus asks during counselling: 'Will the implant cure my tinnitus?' He has read online that it is a tinnitus treatment.
What is the most accurate and responsible way to counsel him?
Module 5 · The Clearest Case: Single-Sided Deafness and Tinnitus
A 44-year-old woman has a profoundly deaf right ear after sudden sensorineural hearing loss two years ago, with a normal-hearing left ear. Her dominant complaint is relentless, intractable right-sided tinnitus; she has tried a CROS aid, which helped her catch speech on the right but did nothing for the noise.
What is the best-supported intervention for her tinnitus, and how should it be framed?
Module 6 · The Hard Cases: When Tinnitus Persists or Worsens
A 50-year-old man with borderline hearing handicap and only occasional, mild tinnitus is implanted, hoping partly for tinnitus relief. Six weeks after activation he reports a new, constant high-pitched tinnitus in the implanted ear that he did not have before, and he is distressed.
What is the most appropriate initial management?
Module 7 · Setting Expectations: Counselling and Managing Tinnitus
A 58-year-old with progressive bilateral severe-to-profound loss says the constant high-pitched ringing in his right ear, worse than his left, is 'ruining his life' and asks whether the implant will cure it. Both ears meet candidacy; his left ear has slightly better residual low-frequency hearing.
How should you counsel him and choose the ear?
Module 8 · The Electrode and the Labyrinth: How Implantation Affects Balance
A 64-year-old with bilateral profound loss is being considered for sequential bilateral implantation. Her first (right) implant went well with no dizziness. Before the second side you note her left ear is her only ear with normal caloric responses; the right has near-absent caloric function.
What is the key balance consideration for the second implant?
Module 9 · Checking the Balance System Around Surgery
A 47-year-old with symmetric bilateral profound loss has no dizziness history. As part of work-up you obtain caloric, vHIT and cVEMP for both ears: the right shows reduced caloric response and absent cVEMP, the left is normal on all three.
Which ear should generally be implanted, and why test at all when she is asymptomatic?
Module 10 · Restoring the Sixth Sense: Why a Vestibular Implant
A 58-year-old develops profound imbalance and 'bouncing vision' while walking, six weeks after a course of intravenous gentamicin for sepsis. She is steady when seated and still but cannot read signs while moving and falls in the dark. Caloric, video head-impulse and rotatory-chair testing show absent responses on both sides. Hearing is normal.
Which statement best explains why a hearing aid or cochlear implant would not help her core complaint?
Module 11 · Building a Vestibular Implant: The Device
During fitting of a vestibular implant, raising the current on the electrode intended for the right horizontal canal produces a brisk eye movement, but the patient also reports a faint sound and develops a visible twitch at the corner of the mouth.
What single phenomenon best accounts for the sound and the facial twitch?
Module 12 · Encoding Head Movement: How It Stimulates
A vestibular-implant recipient is tested on the day of activation and again four weeks later. At activation, head turns produce eye movements that are partly off-axis and the patient finds the sensation disorienting. At four weeks, with daily continuous use, gaze is steadier, reading signs while walking is easier, and the eye movements are better aligned with head motion.
What best explains the improvement between activation and four weeks?
Module 13 · Does It Work? Vestibular Implant Outcomes
A 58-year-old with gentamicin-induced bilateral vestibular loss for 9 years has failed rehabilitation. She is enrolled in a vestibular-implant trial. At one year her dynamic visual acuity has improved, she walks more steadily, and her quality-of-life score is better — but her measured VOR gain is well below normal and the response axis is slightly misaligned.
Which statement best summarises her outcome?
Module 14 · Hearing and Balance Together: The Combined Cochleovestibular Implant
A 62-year-old with end-stage bilateral Meniere's disease has profound hearing loss and disabling bilateral vestibular failure. He cannot localise sound, his speech understanding is negligible, and he falls in the dark. His team considers a vestibular implant but worries about hearing.
Why is this patient an especially logical candidate for a COMBINED cochleovestibular implant rather than a stand-alone vestibular implant?
Module 15 · One Device, Three Senses: The Road Ahead
A patient asks her surgeon: "I've read about an implant that could fix my hearing, my ringing, and my balance all at once. When can I get it?" She has bilateral vestibular loss, profound hearing loss, and disabling tinnitus.
What is the most accurate and honest answer?
Module 1 · When the Cochlear Implant Is the Wrong Answer
A 4-year-old presents with bilateral congenital aural atresia. Both external canals are absent. CT shows normal middle-ear spaces with minor ossicular fusion, and normal, fully formed cochleae and cochlear nerves bilaterally. Behavioural and ABR testing shows a roughly 55-60 dB conductive loss with normal bone-conduction thresholds. The family asks about a cochlear implant they read about online.
What is the most appropriate device-class recommendation?
Module 2 · Mapping the Implantable Hearing Landscape
A 30-year-old has a moderate mixed hearing loss in an ear with a chronically discharging open mastoid cavity. The bone-conduction thresholds are only mildly elevated (sensorineural component about 25-30 dB). A conventional in-the-ear aid blocks the cavity, traps moisture and worsens the discharge. The patient wants a stable solution that does not occlude the ear.
Which device class best fits this anatomy and goal?
Module 3 · How Bone Conduction Works
A patient with a unilateral conductive loss from canal atresia is fitted with a single bone-conduction device on the affected side. During testing the audiologist notes that, even with the good ear masked off, presenting sound through the device produces a response, and the patient reports clearer hearing in noise. A trainee asks how a device on only one side can deliver sound usefully across the head.
What is the correct physical explanation?
Module 4 · Through the Skin: Percutaneous Bone Conduction
A 14-year-old with bilateral aural atresia has worn a percutaneous bone-conduction system since age 6. Over the past year he reports the processor keeps popping off and sounds muffled. On examination the skin around the abutment is thickened and has grown up so that only the very tip of the abutment is visible; the skin is moist and red with some granulation tissue but no frank pus, and the fixture is firmly osseointegrated.
What is the most appropriate next step?
Module 5 · Across Intact Skin: Passive Transcutaneous Bone Conduction
A 9-year-old fitted with a passive transcutaneous magnet bone-conduction implant for bilateral microtia/atresia is brought back because she increasingly refuses to wear the processor. The skin over the implant is red and tender after an hour of use and shows a faint indentation, but there is no breakdown or infection and her aided thresholds when she does wear it are appropriate. Her parents have been using the strongest magnet to stop it falling off during play.
What is the best initial management?
Module 6 · Power Beneath the Skin: Active Transcutaneous Bone Conduction
A 32-year-old radiologist has single-sided deafness after vestibular schwannoma surgery and wants a bone-conduction solution to overcome the head shadow. She has intact, healthy scalp skin, normal hearing in the contralateral ear, and will require periodic surveillance brain MRI for the rest of her life. She is keen to avoid an open abutment for hygiene and cosmetic reasons and asks which implant best fits her situation.
Which option best matches her priorities?
Module 7 · Anchoring Sound to Bone: Implanting Bone-Conduction Devices
A 9-year-old returns four months after single-stage percutaneous bone-conduction implantation for atresia. The skin around the abutment is red and moist with moderate swelling but no granulation tissue and no cellulitis. The processor still couples and hearing is good.
What is the correct Holgers grade and the appropriate first-line management?
Module 8 · Driving the Ossicles: Active Middle-Ear Implants
A 52-year-old with moderate-to-severe sensorineural loss has worn powerful hearing aids for years but cannot tolerate the occlusion and constant feedback, and dislikes any visible external component. The ossicular chain is intact and the ear is healthy. She asks for a solution she can swim and sleep in with nothing showing.
Which device concept best fits her stated priorities?
Module 9 · Where to Clip the Transducer: Coupling and Surgery for Middle-Ear Implants
A patient with mixed hearing loss after multiple chronic-ear operations received a Vibrant Soundbridge with the floating mass transducer placed on the round window. Initial aided thresholds were good, but over a year the benefit faded. Imaging suggests the transducer has shifted within the niche, and bone-conduction thresholds are unchanged.
What is the most likely cause and the appropriate next step?
Module 10 · When the Sound Cannot Get In: Conductive and Mixed Loss
A 34-year-old has a chronically discharging right ear after two failed tympanomastoid surgeries, with an open mastoid cavity. He cannot tolerate an in-the-ear or behind-the-ear aid because of recurrent infection and feedback. Audiometry shows a right air-conduction PTA of 60 dB with a 40 dB air-bone gap; right bone-conduction PTA is 20 dB. The left ear is normal.
What is the most appropriate hearing rehabilitation for the right ear?
Module 11 · One Dead Ear, Three Different Answers
A 41-year-old violinist developed sudden profound left-sided sensorineural hearing loss two years ago after a viral illness; the right ear is normal. She has constant distressing left-sided tinnitus and complains she can no longer tell where instruments are coming from in the orchestra or follow conversation in noisy restaurants. Imaging confirms a patent left cochlea and an intact cochlear nerve.
Which option is most likely to address all of her main complaints?
Module 12 · Reading the Audiogram to Pick the Device
A 28-year-old has bilateral congenital aural atresia with normal-appearing inner ears on CT. Audiometry shows bilateral maximal conductive losses: air-conduction PTA 60 dB, bone-conduction PTA 10 dB, with a 50 dB air-bone gap on both sides. She has never worn amplification because she has no ear canals. She asks which implant she is a candidate for.
Based on reading the audiogram against the device indication boxes, which option fits best?
Module 13 · Reading the Evidence: How Well Do Other Implantable Hearing Devices Work?
A 54-year-old woman with a profoundly deaf right ear and normal hearing on the left reads a manufacturer brochure stating that an active bone-conduction device gives '30 dB of gain and high patient satisfaction.' She asks whether it will let her tell which direction her grandchildren are calling from across a playground.
What is the most accurate counselling response?
Module 14 · Choosing the Right Device: A Decision Framework
A 60-year-old man had a canal-wall-down mastoidectomy years ago and now has a chronically discharging cavity. Audiometry shows a 45 dB air-bone gap with good bone-conduction thresholds and only a mild sensorineural component. A conventional hearing-aid mould triggers infection and cannot be worn.
Which device best fits this patient?
Module 15 · Children and the Horizon: Paediatric Use and the Future of Implantable Hearing
A newborn is diagnosed with bilateral microtia and aural atresia. Newborn hearing screening confirms a bilateral conductive loss with normal-appearing inner ears on imaging. The parents, anxious, ask whether their baby must wait until school age for surgery before anything can be done about hearing.
What is the most appropriate initial management?
Module 1 · When the Cochlea Won't Do: Why a Central Auditory Implant Exists
A 2-year-old born profoundly deaf has had no response to hearing aids. MRI shows a normally formed cochlea on the left but an absent cochlear nerve, with no nerve visible in a very narrow internal auditory canal. The right side shows a common-cavity malformation. The family asks whether a cochlear implant will give their child hearing.
What is the most accurate counselling regarding implantation for this child?
Module 2 · The Cochlear Nucleus Target: A Crowded Corner of the Brainstem
During first activation of a newly placed ABI, the audiologist stimulates each electrode in turn. Most produce sound sensations of varying pitch, but one specific electrode reliably triggers a tickling sensation in the throat and a brief cough, with no useful sound. The patient is otherwise comfortable.
What is the most likely explanation and appropriate action?
Module 3 · From One Electrode to Open-Set Speech: A History of the ABI
Two adults each receive a multichannel ABI at the same centre. The first has NF2 and was implanted after removal of her second vestibular schwannoma. The second became deaf after a temporal bone fracture avulsed both cochlear nerves but has no tumour. A year later the NF2 patient detects environmental sounds and lip-reads better, while the trauma patient understands many sentences by sound alone.
Which statement best explains the difference in outcome?
Module 4 · Who Needs an Auditory Brainstem Implant?
A 4-year-old becomes profoundly deaf after pneumococcal meningitis. CT shows dense new bone filling both cochleae from the round window to the apex, and oblique-sagittal MRI of the internal auditory canals shows cochlear nerves that are present but the scalae are obliterated. At surgery the surgeon cannot pass an array beyond a few millimetres on either side.
What is the most appropriate next step for hearing rehabilitation in this child?
Module 5 · The ABI Device: A Cochlear Implant With a Different Electrode
An NF2 patient activated three months ago tolerates only 11 of her 21 ABI electrodes. The remaining contacts, when stimulated, cause a tingling sensation in the throat, a tug at the corner of the mouth, or transient dizziness rather than sound, so the audiologist has deactivated them. The patient asks why she cannot simply use all the electrodes like a cochlear-implant user.
What best explains why a substantial fraction of ABI electrodes commonly cannot be used for hearing?
Module 6 · The ABI in NF2: Implanting a Distorted Brainstem
A 28-year-old man with NF2 has a growing 3 cm vestibular schwannoma on his only hearing side; the contralateral ear was deafened by previous surgery. He currently understands speech on the telephone in the affected ear. He asks whether an ABI placed when this tumour is removed will let him keep using the phone.
What is the most honest counselling about his likely ABI outcome?
Module 7 · When the Tumour Is Not the Problem: The Non-Tumour ABI
A 41-year-old man became profoundly deaf in both ears after pneumococcal meningitis two years ago. CT shows dense labyrinthitis ossificans obliterating both cochleae from the round window through the basal and middle turns; MRI shows present but encased cochlear nerves. A trial cochlear implant on the better side gave only inconsistent sound detection with severe non-auditory facial twitching. He is highly motivated and understands the risks of posterior fossa surgery.
What is the most appropriate next step?
Module 8 · Hearing for a Brain That Has Never Heard: The Paediatric ABI
A 22-month-old girl has bilateral profound deafness. High-resolution MRI shows bilateral cochlear nerve aplasia with narrow internal auditory canals; the cochleae are hypoplastic. A cochlear implant trial on one side produced no reliable auditory responses behaviourally or on electrophysiology. Her general development is otherwise normal and her family is committed to oral communication.
What is the best next recommendation?
Module 9 · Finding the Lateral Recess: The ABI Operation
During a translabyrinthine ABI after removal of a large vestibular schwannoma, the brainstem is distorted and the usual surface markings are obscured. The surgeon needs a reliable bony and neural reference to locate the foramen of Luschka before sliding the electrode paddle into the lateral recess.
Which landmark is most dependable for locating the foramen of Luschka in this setting?
Module 10 · Finding the Sweet Spot: Intraoperative Monitoring
During translabyrinthine ABI placement in a 34-year-old with NF2, the team records eABR after seating the paddle. A wide bipolar pulse at low current produces two clear peaks at 1.5 and 2.8 ms, but the facial-nerve EMG channel simultaneously shows a brisk response and the anaesthetist reports a transient drop in heart rate.
What is the most appropriate next step?
Module 11 · Activating and Programming the Electric Brainstem
Six weeks after ABI surgery, an NF2 patient is activated in a room with a crash cart available. Of the twelve electrodes, four produce clear sound, three produce sound mixed with a throat tickle, three cause only a body tingle and dizziness, and two give nothing. The patient is upset that speech is not clear and asks whether the implant has failed.
What is the most appropriate management and counselling?
Module 12 · The Non-Auditory Side-Effect Problem
At ABI activation, three electrodes give clear sound, but two of them also produce a strong ipsilateral body tingle and one produces dizziness at the level needed for useful loudness. Six months later the patient returns and reports the tingle is much milder than before.
Which statement best reflects appropriate ABI management?
Module 13 · What an ABI Can Deliver: Outcomes and Honest Expectations
A 34-year-old man with neurofibromatosis type 2 is scheduled for removal of his second vestibular schwannoma with placement of an auditory brainstem implant. He has read online about cochlear implant users who use the telephone and asks whether he can expect the same.
What is the most accurate counselling for this NF2 patient?
Module 14 · Nerve If You Can, Nucleus If You Must: ABI versus CI
A 2-year-old with a severe inner-ear malformation has profound bilateral deafness. High-resolution MRI is equivocal: a very thin cochlear nerve may be present on the right, and none is seen on the left. The cochleae are present but dysmorphic.
What is the most appropriate first step on the right side, following the governing principle?
Module 15 · Higher Up the Pathway: The Auditory Midbrain Implant and the Frontier
An NF2 patient has a well-placed surface ABI confirmed on imaging but, after two years of consistent use and remapping, perceives sound and gains some lip-reading help yet has no open-set speech. He asks whether a deeper or penetrating device would have done better.
Which statement best reflects the current evidence on penetrating and midbrain devices?
Module 1 · The Implant and the Deaf World: Why This Chapter Exists
A skilled CI surgeon meets a profoundly deaf 30-year-old who uses sign language, has a Deaf partner and a satisfying career. The patient came only because a hearing relative insisted, and politely says she has no interest in an implant. The surgeon is genuinely puzzled and feels the patient is refusing an obvious benefit.
What is the most appropriate and respectful response?
Module 2 · Deaf Culture and Identity: A Linguistic Minority, Not a Disability Group
Two Deaf parents who use sign language bring their newly diagnosed profoundly deaf infant to clinic. They are calm and even pleased; their child will share their language and culture. The audiologist, expecting grief, begins counselling about the urgency of early implantation and the risks of delay.
What is the most appropriate framing for this consultation?
Module 3 · Two Models of Deafness: Why the Models Clash, Not the Device
In a candidacy discussion, the surgeon presents strong speech-perception data and recommends early implantation. The deaf father, who signs, responds that he is less worried about speech scores and more concerned that his child have full language and a secure identity. The conversation grows tense; each feels the other is ignoring the obvious.
What is the underlying nature of this disagreement, and the best next step?
Module 4 · From Alarm to Dialogue: A History of the Controversy
A counselor preparing materials for families of newly identified deaf infants wants the written information to reflect how the cochlear implant debate has actually evolved over the past three decades, so that parents are neither alarmed by outdated rhetoric nor given a one-sided medical pitch.
Which approach best reflects the post-2000, matured state of the controversy?
Module 5 · Deciding for a Child: The Core Ethical Tension
Hearing parents of a 9-month-old with profound bilateral deafness ask a clinician whether they should implant now or wait until their child is old enough to decide for herself. They are anxious about choosing for her but also worried about doing harm by waiting.
What is the most accurate and balanced thing to tell them about the core ethical tension?
Module 6 · Best Interests and Real Consent: Deciding Well for a Deaf Child
A family consents to implantation for their toddler after a clinic appointment that covered the operation, its surgical risks, and the expected benefits for spoken language. They were not told about sign language or bilingual options, were given an optimistic single figure for outcomes, and never met any Deaf adults or other families.
From an informed-consent standpoint, what is the principal deficiency here?
Module 7 · The Child's Right to an Open Future
Hearing parents of a profoundly deaf 9-month-old meet a counselor who frames their decision using the child's right to an open future. One relative insists this principle obviously demands immediate implantation; another insists it obviously demands raising the child in the signing Deaf community first. Both invoke Feinberg.
Which statement most accurately reflects how the open-future argument applies here?
Module 8 · Language Deprivation: The Danger Both Sides Fear
A child implanted at 18 months returns at age five. The implant works technically, but device use has been inconsistent and the family was advised to avoid sign so as not to compromise speech. The child has only fragmentary spoken language and no signed language, and now shows delays in vocabulary, memory tasks and emotional regulation.
What does this presentation most likely represent?
Module 9 · Bilingual-Bimodal: Sign and Spoken Together
Hearing parents of a newly implanted 14-month-old ask whether adding sign language will slow their child's speech. They have read one widely cited study suggesting sign exposure was linked to poorer spoken outcomes, and another suggesting native signers do just as well.
What is the most accurate and balanced counseling response?
Module 10 · Is Deafness a Problem to Be Fixed? The Disability-Rights Critique
A hearing couple bring their congenitally deaf 9-month-old to clinic. The audiologist presents cochlear implantation as the standard next step and books surgery. The parents later attend a Deaf-community event and feel they were never told that fluent sign language, or a combined signing-and-implant approach, were real options. They ask the team to revisit the decision.
Which response best reflects an ethically careful, disability-rights-aware approach?
Module 11 · Who Gets to Hear? Equity, Access and Justice
A publicly funded programme in a middle-income country has one paediatric implant slot left this year and two eligible 2-year-olds: one from a wealthy urban family who can readily attend weekly rehabilitation, and one from a low-income rural family for whom travel and follow-up will be difficult but not impossible. Both meet audiological criteria.
From an equity-and-justice standpoint, what is the most defensible programme response?
Module 12 · Choosing Hearing, Choosing Deafness: Genetics and Reproductive Ethics
A culturally Deaf couple, both fluent sign-language users with several deaf relatives, attend a fertility clinic for IVF. They explain that they would like to use preimplantation genetic testing to preferentially transfer an embryo likely to be deaf, so the child will fully share their language and community. The embryologist and counsellor are unsure how to respond.
What is the most ethically and professionally sound first step?
Module 13 · Counselling Families with Cultural Humility
A 3-month-old fails newborn screening and is confirmed to have bilateral profound deafness. Both parents are hearing and visibly distressed. At the first counselling visit the audiologist wants to support the family well over the months ahead, knowing they will later decide about a cochlear implant.
Which approach best reflects culturally humble, non-directive counselling at this stage?
Module 14 · The Adult and Late-Deafened Experience
A 34-year-old who has been profoundly deaf since birth, uses sign language as a first language, works, and is active in the Deaf community attends a clinic at a relative's urging to discuss a cochlear implant. After a full, balanced discussion of realistic outcomes and limitations, she says she is happy with her life as a Deaf person and does not want an implant.
What is the most ethically appropriate clinician response?
Module 15 · Toward Common Ground
Hearing parents of a 6-month-old deaf infant have decided to pursue a cochlear implant. At a counselling visit they ask whether they should also expose their child to sign language, having read online both that it is essential and that it will harm spoken-language development.
Which response best reflects the current emerging consensus?
Module 1 · Hearing in the Real World: Beyond the Test Booth
A 58-year-old, four months post-activation, returns elated. In the booth she scores 96% on AzBio sentences in quiet, up from 12% with hearing aids. But she is in tears describing a recent restaurant evening where she understood almost nothing and felt humiliated. Her husband wonders whether the implant is faulty.
What is the most appropriate next step?
Module 2 · The Problem of Noise: Why a Crowd Is the Enemy
A 41-year-old experienced CI user reports he manages well at work in his quiet private office and on calls, but consistently fails at the weekly team lunch in a tiled cafeteria. He insists his processor is set wrong because, in his words, one extra person talking nearby destroys him even when that person is not loud.
Which mechanism best explains his specific difficulty with a single nearby talker?
Module 3 · Reverberation, Distance and the Tyranny of the Room
A 9-year-old bilateral CI user is reported by her teacher as inconsistent: she answers readily when seated at the front but seems inattentive and frequently mishears when moved to the back of the large, tiled, high-ceilinged classroom. Hearing in the quiet clinic is excellent. The family asks whether her implants are failing.
What best explains the front-versus-back difference and the first-line remedy?
Module 4 · The First Link: Where the Microphone Lives
An adult bilateral cochlear implant user returns six weeks after a successful activation reporting that, on one side only, voices have become progressively muffled and television is harder to follow. Her MAP was stable at the last visit, impedances were normal, and she reports no pain, dizziness or new medical events. On inspection the affected processor's microphone cover looks discoloured.
What is the most appropriate first step?
Module 5 · Pointing the Ear: Directionality and Beamforming
An experienced adult cochlear implant user is delighted with a strongly directional program that transformed restaurant dining. He now complains that he can no longer follow his grandson, who sits behind him in the car, and that he sometimes misses a colleague speaking from his side during meetings. His program is set to a fixed directional pattern that is always active.
What best explains his new difficulty and the most appropriate fix?
Module 6 · Cleaning the Signal: Noise Reduction and Scene Analysis
A recipient who performs well on clinic speech tests reports that open-plan office work leaves her mentally exhausted by mid-afternoon, even though she follows individual conversations adequately. The dominant complaint is the constant hum of ventilation and distant chatter surrounding her, not a single talker she cannot hear. Her speech-in-noise score is essentially unchanged with and without noise reduction enabled.
What is the most appropriate interpretation and management?
Module 7 · Set and Forget: How the Processor Reads the Room
A 68-year-old unilateral cochlear implant user with a modern processor reports she does well at home but struggles in her weekly bridge club, where four players talk across a table in a buzzy hall. At review you find she has six manual programs and has used only program one for two years because, she says, switching is fiddly and by the time she changes it the moment has passed. Her processor supports a single automatic program with scene classification, adaptive directionality and noise reduction.
What is the most appropriate first step?
Module 8 · Bring the Mic to the Talker: Remote and FM/DM Systems
A 19-year-old bilateral cochlear implant user copes well one-to-one but fails in large university lecture halls, where the lecturer speaks several metres away and students murmur throughout. Her processors have automatic scene classification and directionality, which help a little but not enough. She is motivated and tech-comfortable, and her processors support an integrated digital-modulation receiver and direct 2.4 GHz streaming.
Which intervention will most improve her access to lectures?
Module 9 · The Invisible Cable: Telecoils and Hearing Loops
A 72-year-old unilateral cochlear implant user enjoys her processor at home and with a streaming accessory for the television, but says she cannot follow the sermon at her place of worship, a large reverberant hall. She has noticed a sign at the entrance showing an ear symbol with a small T. Her processor has a telecoil and supports an automatic telecoil mode, but she has never used it.
What is the most appropriate advice?
Module 10 · Cutting Out the Room: Bluetooth and Direct Audio Streaming
A 14-year-old bilateral CI user reports excellent direct streaming from her father's iPhone for video calls but says she cannot stream anything from her own new Android phone, despite the processor being modern and the iPhone working flawlessly. Her processor brand advertises both MFi and ASHA support.
What is the most likely explanation and first step?
Module 11 · The Ecosystem Around the Ear: Accessories, Apps and Telecare
A bilateral CI user buys a TV streamer and reports that television is clearer than before but oddly 'lopsided', with a strong signal in the right ear and a faint, room-coloured sound on the left. Both processors are charged and working for face-to-face conversation.
What is the most likely cause?
Module 12 · Beyond the Device: Assistive Listening and Real-World Accessibility
A 30-year-old unilateral CI user who removes his processor to sleep tells you he slept through a smoke alarm during a small kitchen fire and was woken only by a housemate. He is otherwise delighted with his implant and streaming. He asks whether a more powerful program would have helped.
What is the most appropriate advice?
Module 13 · Beyond the Booth: Measuring Real-World Benefit
A 58-year-old unilateral implant user returns six months after activation. In the sound booth she scores 95% on sentences in quiet, and her map looks well balanced. Yet she reports that work meetings and family dinners are exhausting and that she often misses what people say. Her processor datalog shows good wear time, with a large fraction of her day logged in speech-in-noise environments.
What is the most appropriate next step to characterise her difficulty?
Module 14 · The Coached Listener: Counselling for Daily Listening
A 34-year-old implant user with strong booth and speech-in-noise scores complains bitterly about weekly team meetings in a glass-walled conference room. On questioning, she owns a remote microphone accessory but says she feels awkward asking colleagues to use it and so leaves it in her bag. Her datalog confirms heavy time in speech-in-noise scenes and no accessory streaming.
What is the most appropriate primary intervention?
Module 15 · The Listening Machine: The Future of Real-World Hearing
A well-informed 40-year-old implant user has read a press article claiming that brain-controlled hearing aids can read your mind to pick out the voice you want. He asks whether he should wait to be implanted, or delay an upgrade, until this technology is available, since meetings remain his biggest struggle.
What is the most appropriate counselling response?
Module 2 · Impedance & electrode interface
A 4-year-old, implanted 18 months ago, is brought in by parents who report she has become less responsive to her name over the last two visits. Speech-perception scores have dropped. At today's session, electrode 3 shows an impedance of 28 kΩ against a 4–6 kΩ profile elsewhere; three visits ago it read 7 kΩ.
What does the impedance finding tell you, and what is the immediate programming step?
Module 3 · ECAP / Neural Response Telemetry
At first fitting of a congenitally deaf 2-year-old, AutoNRT returns no measurable response on the three apical electrodes you try. The audiologist is concerned the auditory nerve is non-functional and questions whether the implant will work.
What is the most appropriate next step before drawing conclusions about the nerve?
Module 4 · ECAP threshold & functions
An adult CI user with normal impedances and measurable ECAP thresholds across the array nonetheless struggles with speech in noise and music. On testing, the spread-of-excitation functions for several mid-array electrodes are unusually broad and overlapping.
What do the broad SOE functions suggest, and how might they guide programming?
Module 5 · Electrical stapedius reflex
You are activating a 14-month-old who, predictably, cannot give reliable loudness judgements. ECAP thresholds were recorded at surgery. Post-operatively you obtain clear ESRTs on electrodes 3, 11 and 20 using contralateral immittance.
How should the ESRTs inform your initial MAP?
Module 6 · Electrically-evoked ABR
A child with profound deafness has a small cochlear nerve on MRI, and the team is uncertain whether to proceed with a cochlear implant or plan for an auditory brainstem implant. At implantation, you record eABR under the surgical anaesthetic and obtain a clear, replicable wave eV at moderate stimulation levels.
How does the eABR result inform the decision?
Module 7 · Electrical cortical responses
A 5-year-old with a long history of un-aided profound deafness is implanted. The family asks for objective evidence about how the child's brain is adapting. Serial cortical recordings over the following year show a P1 latency that shortens but remains above the age-normal range.
How should you interpret and communicate this?
Module 8 · Intraoperative ECochG
During a hearing-preservation cochlear implantation, you monitor the cochlear microphonic to a 500 Hz tone burst through the apical electrode. Insertion proceeds smoothly with a stable-to-rising CM until, three-quarters of the way in, the amplitude falls abruptly by about 40%.
What is the appropriate intraoperative response?
Module 9 · Objective measures → the MAP
An adult is activated four weeks after implantation. Impedances are normal. You obtain ECAP thresholds across the array and clear ESRTs on three electrodes. The patient finds formal loudness scaling difficult on the day and tires quickly.
What is the most appropriate way to build the initial MAP?
Module 10 · Troubleshooting & special cases
A long-standing CI user returns with gradually worsening speech understanding over a year. Integrity testing passes. Impedances are within the normal range today, but reviewing the chart shows several basal electrodes have crept upward over four visits. There is no effusion and the MAP is unchanged.
What does the pattern suggest and what is the next step?
Two weeks after activation, a recipient with a history of otosclerosis reports their cheek twitches whenever the environment is loud. The effect is reproducible and bothersome. Impedances are normal.
What is the most appropriate objective-measures-guided management?
Module 11 · Manufacturer systems compared
A patient transfers to your clinic with a summary from another centre that lists 'tART thresholds' and 'MCL values in charge units'. Your clinic primarily programs Cochlear devices and your team is used to tNRT and C-levels in current-level steps.
How should you use the outside report?
Module 13 · Future directions, AI & emerging tech
Your clinic is piloting a machine-learning tool that predicts a full MAP from impedance and ECAP data. For a new adult recipient it proposes C-levels noticeably higher than your usual first-fit, and the patient — who can give some loudness feedback — reports two of the channels as uncomfortably loud at the suggested levels.
How should you use the AI-suggested MAP?