Assessing binaural/bimodal advantages using auditory event-related potentials in subjects with cochlear implants

Area of Science:

• Audiology
• Neuroscience
• Biomedical Engineering

Background:

• Cochlear implants (CI) aim to restore hearing but optimal configurations for speech perception remain under investigation.
• Binaural (two CIs) and bimodal (CI plus contralateral hearing aid) hearing strategies are increasingly used.
• Objective measures like auditory event-related potentials (ERPs) can complement subjective speech perception tests.

Purpose of the Study:

• To evaluate the benefits of binaural and bimodal hearing in cochlear implant users.
• To compare speech perception and auditory processing using event-related potentials (ERPs) across different hearing conditions.

Main Methods:

• Compared speech perception in quiet using monosyllabic words for binaural CI users (CI/CI) and bimodal CI/hearing aid (HA) users.
• Measured late cortical ERPs (N1, N2, P3 latencies) during an auditory oddball task.
• Assessed monaural, binaural, and bimodal hearing conditions in subjects with over 6 months of device use.

Main Results:

• Both binaural and bimodal hearing significantly improved speech perception over monaural hearing (p<0.01).
• N2 and P3 latencies were significantly shorter in binaural and bimodal conditions compared to monaural (p<0.01).
• N1 latency showed no significant change, while P3 latency correlated with speech perception improvements.

Conclusions:

• Binaural and bimodal hearing configurations enhance speech perception in cochlear implant users compared to monaural fitting.
• Auditory event-related potentials, particularly P3 latency, serve as a reliable objective measure of these auditory benefits.
• The study recommends bilateral hearing device use for cochlear implant recipients to maximize auditory function.