Speech perception in modulated noise assessed in bimodal CI users

Area of Science:

• Audiology
• Neuroscience
• Speech and Hearing Sciences

Background:

• Cochlear implants (CIs) provide good speech perception in quiet but struggle with speech in noise.
• Bimodal CI fitting (CI in one ear, hearing aid (HA) in the other) performance in noise is influenced by residual acoustic hearing.
• Hearing loss severity correlates with reduced speech perception in noise.

Purpose of the Study:

• To investigate speech perception in noise for bimodal CI users.
• To compare bimodal CI users with age-matched HA users and individuals with normal hearing (NH).
• To assess performance across different noise conditions and participant groups.

Main Methods:

• Participants included 19 bimodal CI users, 39 HA users, 40 older NH subjects (60-90 years), and 14 young NH subjects.
• Speech reception thresholds (SRTs) were measured using the Oldenburg Sentence Test.
• Two spatial conditions (S0N0 and multisource-noise field) and two noise types (continuous Ol-noise and modulated Fastl-noise) were used.

Main Results:

• SRTs worsened significantly with increasing hearing loss across all conditions.
• Bimodal CI users performed worse than young NH individuals in both continuous and modulated noise conditions.
• Older NH individuals showed limited benefit from gap listening, while HA and bimodal CI groups showed no gap listening effect and worse performance in modulated noise.

Conclusions:

• Speech perception in modulated noise is more challenging than in continuous noise for individuals with hearing loss.
• Hearing loss severity is a critical factor impacting speech-in-noise performance.
• Bimodal CI users and HA users face significant difficulties in noisy environments, particularly with modulated noise.