The Effect of Stimulation Timing on Sound Source Localization in Patients with Cochlear Implant and Hearing Aid
* Presenting author
Abstract:
Introduction: Patients with asymmetric hearing loss are typically supplied with a cochlear implant (CI) in one ear and wear a hearing aid on the contralateral side. These patients develop binaural hearing abilities in aided condition even if transfer of signals to the auditory system differs between CI and hearing aid. This work summarizes sound localization results of such patients after modification of stimulation timing on the CI side.Methods: Participants of the study were supplied with a CI of type MED-EL, Generation i1000/i1200 in one ear and were using a hearing aid on the contralateral side. A considerable binaural benefit in best aided condition was required. Stimulation timing on the CI side was varied by delaying the CI signal. A series of sound localization tests were performed for different delay times.Results: The study group showed large deficits in sound localization irrespective of modifying stimulation timing, particularly for stimuli from front, left or right. At angles of ±30° and ±60° judgements were more accurate and timing of the CI signal had a significant effect on the localization error. Conclusion: Stimulation timing of the CI seems to affect binaural hearing performance in listeners with bimodal supply (hearing aid and cochlear implant).