Enhancement of Interaural Level Differences and Binaural Band Selection Improves Sound Localization in Bilateral Cochlear Implant Users
* Präsentierender Autor
Zusammenfassung:Bilateral cochlear implant (BiCI) users have difficulties localizing sounds, mainly due to the distortion of interaural differences in level and in time (ILD and ITD). In this work, we aim at emphasizing ILD cues to improve sound source localization in BiCIs. In this work, an ILD enhancement method that emphasizes interaural differences in level to exploit the available electric dynamic range, and binaural band selection to keep coherent stimulating bands across ears are investigated to help BiCI listeners. Horizontal plane sound-source localization performance of five BiCI listeners was evaluated in a virtual sound field, under direct computer control of bilaterally synchronized stimulation. The results indicate that the participants were able to discriminate the direction of arrival more accurately for narrow azimuths when the ILD enhancement was applied, compared to the natural ILD and independently of binaural band selection. On the other hand, localization abilities improved for wider azimuths when using binaural band selection compared to independent band selection, regardless of whether ILD enhancement was applied or not. The outcomes of this work show that the proposed ILD enhancement method, besides binaural band selection, improves the localization of sound sources in the front horizontal plane.