14Choosing the Strategy: Bilateral, Bimodal or Wait

FThe first question: what is in the contralateral ear?

Useful aidable acoustic hearing in the other ear (especially low-frequency residual) favours trying bimodal first: a CI on one side, a hearing aid on the other. Bimodal listening adds low-frequency fine structure and improves intelligibility, sound quality and listening effort over the CI alone, though the size of benefit varies between individuals. Little or no useful acoustic hearing on the second side shifts the balance toward a second cochlear implant, since a hearing aid there contributes little.[2013][2017]

CAge, development and the cost of waiting

In children, the sensitive period for binaural development argues for early bilateral implantation (simultaneous or short-interval sequential) to lay down spatial-hearing pathways. Long inter-implant delays in sequentially implanted children are associated with poorer integration of the second ear; younger second-side age and shorter gaps are better. In adults, 'wait' is a legitimate arm — observing a stable, well-performing bimodal user — but a long delay before a second CI risks reduced second-ear benefit from auditory deprivation.[2006][2015]

CEtiology, residual-hearing risk and patient goals

Progressive or fluctuating etiologies threaten the residual hearing that makes bimodal worthwhile, sometimes tipping the decision toward a second CI before that hearing is lost. Goal-driven choice: priorities for music quality, speech-in-noise and reliable localization push toward two well-matched ears (bilateral CI or a strong bimodal fit). Device and fitting factors matter: bimodal success depends on careful loudness balancing and frequency/timing matching between the CI and the HA, not just on prescribing both.[2013][2017]

CAn algorithm to tie it together

Step 1 — children: default to early bilateral CI (simultaneous, or sequential with the shortest feasible gap), regardless of small residual hearing, to protect binaural development. Step 2 — adults with aidable contralateral hearing: trial bimodal with optimized fitting; convert to a second CI if benefit is poor or residual hearing is being lost. Step 3 — adults with little contralateral hearing: offer a second CI, weighing life expectancy, goals and reimbursement; 'wait' is reserved for stable, satisfied bimodal users or where cost/access forbids a second device.[2013][2006][2017]