Single-Sided Deafness: Using Cortical Auditory Evoked Potential to Improve Cochlear Implant Fitting

Objective To investigate if acoustic cortical auditory evoked potential (aCAEP) measures can be used to verify the cochlear implant (CI) map and consequently improve auditory outcomes in adults with single-sided deafness (SSD). Design aCAEPs were measured in SSD-CI recipients using speech tokens /m/, /g/, /t/, and /s/. If aCAEP responses were present for all speech tokens at the outset, no map adjustments were implemented. If aCAEP responses were absent for one or more tokens, the map was adjusted until aCAEPs were observed for all four tokens. Speech in noise testing using BKB-SiN was performed before and after aCAEP recording. The results of the speech testing results at presurgery, 6, 12, and 24 months post-CI were also analyzed. Results Sixty-seven CI users with SSD participated in this study. All CIs had been mapped according to the conventional subjective loudness perception method. Twenty-three SSD-CI users exhibited an aCAEP response for all four speech tokens and were therefore considered optimized at outset. Forty-four participants lacked an aCAEP response from at least one speech token and had their most comfortable levels adjusted accordingly. Of these, map adjustments allowed aCAEPs to be elicited for all four speech tokens in 23 individuals. Speech in noise testing significantly improved pre– to post–aCAEP-based adjustment. Conclusion aCAEP recordings were successfully used to verify CI mapping and improve resultant speech outcomes in SSD-CI users.