Enhancement of interaural level differences for bilateral cochlear implant users.

Area of Science:

• Audiology
• Neuroscience
• Biomedical Engineering

Background:

• Bilateral cochlear implant (BiCI) users exhibit poorer sound localization than normal hearing (NH) listeners.
• NH listeners utilize interaural level differences (ILDs) and interaural time differences for sound localization.
• Current BiCI systems inadequately represent these binaural cues.

Purpose of the Study:

• To investigate methods for improving ILD coding in BiCI systems.
• To enhance the representation of spatial auditory information for BiCI users.

Main Methods:

• Two ILD enhancement strategies were explored: artificial current-versus-angle function and bilaterally linked N-of-M band selection.
• Participants' sound localization accuracy was assessed using these enhanced ILD coding methods.

Main Results:

• Sound source discrimination improved at narrow azimuths with ILD enhancement compared to natural ILDs.
• Linked N-of-M band selection positively impacted left/right discrimination at larger azimuths for a subset of participants.

Conclusions:

• ILD enhancement techniques show promise in improving sound localization for BiCI users.
• Linked N-of-M band selection may further benefit spatial discrimination in some individuals.