Effects of bilateral cochlear implants on vocal intensity control

Abstract

Bilateral Cochlear Implants (BiCIs) can improve many perceptual tasks, including speech perception in noise, when compared to unilateral implantation. However, evidence suggests that BiCI users may perform worse on some vocal tasks, such as F0 production, than when using their better ear alone. This research aimed to determine if this detrimental effect on vocal control with BiCI devices extends to the control of vocal amplitude variations. Ten BiCI users were asked to produce a sustained vowel vocalization using both CIs and one CI separately. Their recordings were analyzed acoustically to determine long-term control of amplitude variations using the Variation of Peak Amplitude (vAm). The preliminary findings showed that using both CIs resulted in less control over vocal intensity for eight participants when compared to using one ear alone. The other two participants either showed no difference between the conditions or had a higher vAm with the unilateral ear than with the bilateral condition. The result suggests that BiCI use might detrimentally affect controlling long-term vocal intensity variation beyond any effects of unilateral CIs. Further investigation is needed to address how the vocal intensity control in BiCI users is affected.