Lateralization of Interaural Level Differences in Multi-Channel Electrical Stimulation

Lateralization of Interaural Level Differences in Multi-Channel Electrical Stimulation Olga Stakhovskaya, Tanvi Thakkar, Matthew Goupell University of Maryland College Park Background Improved sound localization is one of the benefits associated with use of bilateral cochlear implants (CIs). Modern speech processors cannot reliably encode all of the localization cues available to normal-hearing listeners. Therefore, CI listeners rely mostly on interaural level differences (ILDs) to produce a spatial impression of the surrounding environment. The thresholds (T) and the "most-comfortable" (C) levels obtained during the mapping procedures often differ across the electrodes within the ear and across the ears, resulting in a different spread of excitation at different cochlear locations. Moreover, real world sounds can activate multiple electrodes simultaneously. It is unclear if multi-electrode stimulation with current spread can produce a centered and punctate auditory image in a CI user's head, which could be used as a baseline to create a consistent spatial map across frequencies.