3The First Switch-On

CGetting ready to go live

Activation is typically two to four weeks post-op; the audiologist begins with otoscopy and incision inspection, removes cerumen if needed, and selects coil magnet strength before any sound is delivered. Once the processor is connected, electrode impedances are measured; at initial activation impedance is frequently high but falls with routine use, and open or short circuits are disabled before programming. Electrode conditioning, a low-level current pass that helps clear air bubbles and protein buildup from the contacts, may be run at activation or before stimulating previously disabled electrodes. The audiologist then selects the signal coding strategy and base parameters, commonly starting around an initial stimulation rate of 900 to 1500 pulses per second depending on the device.[2020]

FWhat electric sound first sounds like

The threshold programming signal is perceived by most users as two to three beeps, similar to pure-tone audiometry, though some report a scratchy, buzzing, or static-like quality. When live speech is first delivered, many recipients describe voices as robotic, mechanical, or pitch-shifted, like a cartoon character or a chipmunk, and some say speech sounds more like beeps or noise. This unnatural quality is expected because the deprived auditory brain must adapt to a fundamentally new signal, and considerable improvement typically unfolds over the following weeks and months. A young child's first response varies widely, from crying or stilling at play to a glance, a changed sucking pattern on a pacifier, or no obvious response at all, and none of these predicts eventual outcome.[2020][2009]

CSetting a conservative first map and going live

Because T levels will shift over the first weeks, the audiologist uses larger step sizes at the first session, for example a 5-unit ascending and 10-unit descending step at initial stimulation, refining with smaller steps later. Experienced or attentive recipients may use smaller 2-unit ascending and 4-unit descending steps, and small steps are advised whenever the dynamic range is narrow (under about 15 units). Comfort levels are commonly set in live speech mode: the audiologist activates the processor microphone and raises C/M levels globally to a comfortable percept, then balances loudness across channels and trims back to optimal comfort. Because stimulation grows logarithmically, near the top of the range even a 1 to 2 unit global change can produce a noticeable jump in loudness and clarity, so adjustments are made in precise small steps.[2020][1994]

CManaging first impressions and the early visit schedule

Before going live the audiologist explicitly warns adults they may leave thinking they made a mistake and that voices may sound cartoonish, reassuring them that the brain needs time and that improvement will come. Activation is often delivered as a two-day session, about 2 hours on day 1 and 1.5 hours on day 2, the second day letting the recipient feed back early listening experiences for fine-tuning. After the two-day activation recipients return at one week, when impedances have usually fallen and stabilised, T levels are remeasured on as many channels as possible, and sound-field thresholds are checked. A one-month visit follows, reinforcing care, backup equipment, and habilitation, after which the schedule for future programming appointments is planned as levels and performance continue to evolve.[2020][2002]