Horizontal Sound Localization in Cochlear Implant Users with a Contralateral Hearing Aid.

Horizontal Sound Localization in Cochlear Implant Users with a Contralateral Hearing Aid. Hear Res. 2016 May 10; Authors: Veugen LC, Hendrikse MM, van Wanrooij MM, Agterberg MJ, Chalupper J, Mens LH, Snik AF, John van Opstal A Abstract Interaural differences in sound arrival time (ITD) and in level (ILD) enable us to localize sounds in the horizontal plane, and can support source segregation and speech understanding in noisy environments. It is uncertain whether these cues are also available to hearing-impaired listeners who are bimodally fitted, i.e. with a cochlear implant (CI) and a contralateral hearing aid (HA). Here, we assessed sound localization behavior of fourteen bimodal listeners, all using the same Phonak HA and an Advanced Bionics CI processor, matched with respect to loudness growth. We aimed to determine the availability and contribution of binaural (ILDs, temporal fine structure and envelope ITDs) and monaural (loudness, spectral) cues to horizontal sound localization in bimodal listeners, by systematically varying the frequency band, level and envelope of the stimuli. The sound bandwidth had a strong effect on the localization bias of bimodal listeners, although localization performance was typically poor for all conditions. Responses could be systematically changed by adjusting the frequency range of the stimulus, or by simply switching the HA and CI on and off. Localization responses were largely biased to one sid...
Source: Hearing Research - Category: Audiology Authors: Tags: Hear Res Source Type: research