Bimodal stimulation in cochlear implant users: matrix test speech-in-noise performance and audiological...

Area of Science:

• Audiology
• Hearing Science
• Biomedical Engineering

Background:

• Unilateral cochlear implant (CI) users with hearing loss in the opposite ear face a choice: contralateral hearing aid (HA) or CI-only listening.
• Bimodal stimulation (BS), combining electric (CI) and acoustic (HA) input, often enhances speech perception in noise.
• Some patients decline contralateral HA use despite having residual hearing.

Purpose of the Study:

• Characterize audiological profiles of CI recipients who refuse contralateral HA use.
• Compare speech-in-noise performance between BS users and CI-only users.
• Evaluate the benefit of BS using the Italian Matrix Sentence Test.

Main Methods:

• Recruited unilateral CI users with moderate-to-profound contralateral sensorineural hearing loss.
• Divided participants into BS users and CI-only users.
• Assessed pure-tone audiometry (PTA), word recognition score (WRS), and speech-in-noise performance; BS users were tested with and without HA.

Main Results:

• No significant differences in PTA or WRS in quiet between BS and CI-only groups.
• BS users showed significantly improved speech-in-noise performance with CI+HA compared to CI-only listening.
• CI-only users exhibited slightly better residual contralateral hearing.

Conclusions:

• Bimodal stimulation (BS) offers a significant within-subject advantage for speech perception in noise.
• Refusal of contralateral amplification may stem from perceived limited benefit.
• Individualized counseling and outcome-based selection are crucial for hearing device choice.