Timing of bilateral sequential cochlear implantation for children: determination of its benefit

Purpose: To evaluate monosyllable word recognition in noise under different conditions in bilateral sequential cochlear implants (CIs). Second, to assess subjective hearing benefits among bilateral sequential CIs, bimodal hearing, and CI-only groups. Lastly, to analyze the prognostic factors affecting CI outcomes in children with bilateral sequential CIs.

Methods: Sixty-five children with CI were enrolled. Mandarin monosyllable recognition tests in noise and the Speech, Spatial, and Qualities of Hearing Scale (SSQ) were used to assess post-CI outcomes. The SSQ benefits were compared among children with bilateral CIs, bimodal hearing, and CI-only.

Results: Bilateral CIs significantly outperformed the first or second CI alone using in noise. The bilateral CI group had significantly better SSQ scores for speech, qualities, and total scores compared to the CI-only group. Additionally, 41% of the variance in speech perception of the second CI can be attributed to the inter-implantation interval between bilateral CIs.

Conclusion: Bilateral sequential CIs can enhance speech perception in noise and daily life-functioning for children. Earlier implantation of bilateral sequential CIs results in better outcomes, while inter-implantation interval exceeding 9.6 years between bilateral CIs may lead to poor second CI performance in noise. Therefore, early bilateral sequential CIs should be encouraged.