Speech-perception-in-noise and bilateral spatial abilities in adults with delayed sequential cochlear implant

Area of Science:

• Audiology
• Neuroscience
• Biomedical Engineering

Background:

• Bilateral cochlear implantation (CI) aims to improve speech perception in noise.
• Delayed sequential implantation involves receiving the second CI after a significant delay.
• Understanding bilateral benefits is crucial for optimizing hearing outcomes.

Purpose of the Study:

• To assess speech-in-noise perception in adults with delayed sequential CIs.
• To quantify bilateral spatial benefits, including head-shadow effect, summation, squelch, and spatial release from masking.
• To compare these benefits with findings from simultaneous or earlier sequential CI recipients.

Main Methods:

• Cross-sectional, one-group, post-test-only exploratory design.
• Eleven adults with severe-to-profound bilateral sensorineural hearing loss received delayed sequential CIs.
• Speech-in-noise perception was evaluated using standardized sentences and an adaptive procedure to determine signal-to-noise ratio (SNR) for speech reception threshold (SRT).

Main Results:

• Minimal and non-statistically significant bilateral benefits were observed for speech-in-noise perception.
• The head-shadow effect at 180 degrees demonstrated the most robust bilateral spatial benefit.
• Improved perception in spatially distinct conditions suggested a greater contribution from the second CI (CI 2) than the first (CI 1).

Conclusions:

• Bilateral benefits in delayed sequential CI recipients are less pronounced than in simultaneous or earlier sequential recipients.
• The degree of bilateral benefit appears linked to the availability of the ear with the most favorable SNR.
• Delayed implantation may result in reduced binaural integration and benefit.