Bilateral Cochlear Implants Allow Listeners to Benefit from Visual Information When Talker Location is Varied

Area of Science:

• Audiology
• Neuroscience
• Biomedical Engineering

Background:

• Previous studies showed bilateral cochlear implants (CIs) improve speech understanding with visual cues, unlike unilateral CIs.
• This is likely due to bilateral CI users' better sound-source localization enabling them to use visual information effectively.

Purpose of the Study:

• To validate prior findings on auditory-visual speech understanding with bilateral CIs.
• This study used a different test environment, CI type, materials, and response measure to ensure robustness.

Main Methods:

• Nine bilateral CI users were tested in a simulated restaurant environment.
• Auditory-visual sentences were presented with visual cues in noise, comparing one CI versus bilateral CIs, with and without visual information.

Main Results:

• Bilateral CIs with visual cues yielded 84% word recognition, significantly higher than unilateral conditions (43-52%).
• Visual information substantially improved performance for bilateral CI users but not unilateral users.
• The benefit of bilateral CIs was amplified in auditory-visual conditions compared to auditory-only.

Conclusions:

• Bilateral CIs offer substantial benefits for speech understanding in complex auditory-visual environments.
• Standard testing may underestimate the true value of bilateral CIs for speech perception.