1Overview — will the implant beat the aid?
This is where the atlas turns clinical. The foundations chapters explained the ear, the brain, the causes of deafness, the device, and why hearing aids eventually fall short. Now the question becomes practical and personal: should this patient have a cochlear implant? Candidacy is not a single number read off an audiogram but a multidisciplinary judgement, built from many sources, about whether the benefits of implantation are likely to outweigh its risks — and, above all, whether electrical hearing will materially improve on what the patient can already achieve with their best-fitted hearing aids. This chapter follows that judgement from the first audiogram to the decision to operate: how the criteria evolved, how candidacy is measured, what predicts the result, and how a team weighs it all.
FWhat this chapter is
Chapter 9 ended at the crossover — the point where a hearing aid has done all it can. This chapter is about recognising and acting on that point: the formal assessment of candidacy for a cochlear implant. It is the first of the clinical chapters, and the gateway to surgery, devices and programming that follow.[2009]
FThe central question
Strip candidacy to its core and one question remains: will this person understand more through an implant than through their best hearing aids? Everything else — the audiometry, the imaging, the counselling — serves that comparison. Candidacy is therefore a judgement about relative benefit, weighed against the risks of surgery and the commitment of rehabilitation.
FThe tipping point
Plot the implant's predicted result against the patient's current aided performance and a boundary appears — a tipping point between candidacy and non-candidacy. Comfortably above it, the implant clearly wins; comfortably below, the aid is still better; near it, the decision is genuinely difficult. That boundary is not fixed: as implants have improved it has moved, letting in patients who once would not have qualified (Module 2).
FA multidisciplinary judgement
Because deafness reaches into communication, education, work and emotion, no single clinician or test can decide candidacy. It is a multidisciplinary process — audiology, otology, imaging, speech-language, psychology and more — and the best decisions come from a team that can weigh anatomy, motivation, expectations and support alongside the audiogram. Indeed, a careful assessment sometimes concludes not to implant.
FChapter roadmap
| Movement | Modules | What they cover |
|---|---|---|
| The criteria | 2–4 | How candidacy evolved; the audiological battery; and the audiometric and sentence-score criteria. |
| Predicting & screening | 5–7 | What predicts the outcome; the medical and otologic work-up; and the role of imaging. |
| People & expansion | 8–10 | Paediatric candidacy; the expanding indications; and psychosocial assessment and expectations. |
| Deciding | 11–12 | Which ear and how many; and the multidisciplinary team decision. |
We begin with how the very definition of a candidate has changed — how the criteria evolved (Module 2).
What is the central question candidacy must answer?
What is the central question of cochlear-implant candidacy?
Who makes the candidacy decision?