Single-Sided Deafness and Cochlear Implants: Performance in a Novel Combined Speech-in-Noise and Localization Task

Area of Science:

• Audiology
• Neuroscience
• Biomedical Engineering

Background:

• Single-sided deafness (SSD) presents significant challenges in auditory perception, affecting sound localization and speech comprehension in noisy environments.
• Compensatory head movements are a known adaptation strategy for individuals with hearing impairments.

Purpose of the Study:

• To analyze the impact of SSD on listening behavior, including sound localization and speech-in-noise performance.
• To quantify and compare compensatory head movements in individuals with normal hearing (NH) and SSD, with and without a cochlear implant (CI).

Main Methods:

• A prospective study involving participants with NH, SSD, and SSD with CI.
• Subjects performed speech-in-noise and sound localization tasks in a controlled acoustic environment while head movements were monitored.
• Analysis focused on localization accuracy, speech-in-noise performance, and head movement metrics (displacement, onset delay, response time).

Main Results:

• SSD subjects showed reduced accuracy in speech-in-noise and sound localization compared to NH controls.
• Cochlear implantation provided limited benefit for sound localization but improved speech-in-noise performance, especially at optimal signal-to-noise ratios (SNRs).
• Cochlear implant users exhibited shorter head movement response times, though onset delay and displacement did not differ significantly from SSD-only participants.

Conclusions:

• Cochlear implants primarily enhance speech-in-noise performance for individuals with SSD.
• While sound localization abilities exist, their clinical significance may be modest.
• Adaptive head movement strategies could be leveraged through device programming or training to further improve auditory performance in SSD.