Auditory spatio-temporal interactions in single-sided deaf patients with unilateral cochlear implants

There is a growing use of unilateral cochlear implants (CIs) as a promising intervention for patients with single-sided deafness (SSD), especially to improve speech perception in noisy environments and sound localization performance. However, the effectiveness of CIs in improving spatial hearing for this population remains uncertain. Traditional sound localization tasks are often lengthy and cognitively taxing for individuals who struggle to identify sound source locations. This study introduces a new task for evaluating the restoration of auditory spatial cues in SSD-CI users by examining the biasing effects of spatial location on timing judgments for sequential sounds. The auditory spatial kappa (ASK) effect manifests as a bias in perceived relative onset timing between subsequent sounds as a function of the spatial distance between them. Sounds that are farther in space are judged as farther apart in time compared to sounds presented closer in space. We tested the degree of spatial bias on temporal judgments in SSD patients with and without their CI to evaluate the restoration of spatial cues with CI in different frequency ranges. Results indicate that the ASK task may be a useful tool for implicitly assessing spatial hearing in clinical populations who perform poorly on traditional sound localization tasks. [Funding: NIH F32DC022162 (CK)]