Best Cochlear Locations for Delivering Interaural Timing Cues in Electric Hearing

TL;DR

This study explores how to best use cochlear implants to restore the ability to detect sound location by improving interaural timing cues.

Contribution

The study identifies optimal cochlear locations for delivering interaural timing cues in electric hearing.

Findings

Effective ITD perception with BiCIs depends on targeting cochlear locations that transmit information most effectively.

These optimal locations can occur anywhere along the cochlea, not just in the apical region.

The findings challenge assumptions about where ITD cues are best encoded in electric hearing.

Abstract

Growing numbers of children and adults who are deaf are eligible to receive cochlear implants (CI), which provide access to everyday sound. CIs in both ears (bilateral CIs or BiCIs) are becoming standard of care in many countries. However, their effectiveness is limited because they do not adequately restore the acoustic cues essential for sound localization, particularly interaural time differences (ITDs) at low frequencies. The cochlea, the auditory sensory organ, typically transmits ITDs more effectively at the apical region, which is specifically “tuned” to low frequencies. We hypothesized that effective restoration of robust ITD perception through electrical stimulation with BiCIs depends on targeting cochlear locations that transmit information most effectively. Importantly, we show that these locations can occur anywhere along the cochlea, even on the opposite end of the frequency map from where ITD cues are most dominantly encoded in an acoustic hearing system.

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