Using the Mismatch Negativity to Evaluate Hearing Aid Directional Enhancement Based on Multistream Architecture

Area of Science:

• Auditory Neuroscience
• Speech Perception
• Hearing Aid Technology

Background:

• Hearing loss impacts speech perception in noise.
• Mismatch negativity (MMN) reflects preattentive auditory processing.
• Hearing aid features aim to improve speech understanding.

Purpose of the Study:

• To investigate if hearing aid directivity, specifically multistream architecture (MSA), enhances mismatch negativity (MMN) to phonemic contrasts in noise.
• To assess the impact of MSA on preattentive speech processing in older adults with hearing loss.

Main Methods:

• A single-blind, within-subjects study with 15 older adults with moderate-to-severe hearing loss.
• Participants completed a phonemic discrimination task to determine individualized signal-to-noise ratios (SNRs).
• MMN was measured during passive listening to phonemic oddball sequences with MSA enabled (MSA-ON) and disabled (MSA-OFF).

Main Results:

• MMN magnitudes were significantly larger in the MSA-ON condition compared to MSA-OFF.
• MMN magnitudes showed a positive correlation with the degree of hearing loss.
• MMN latency was influenced by the interaction between hearing aid condition and individualized SNRs, particularly in the MSA-OFF condition.

Conclusions:

• Hearing aid directivity utilizing MSA enhances preattentive detection of phonemic contrasts in noisy environments.
• The MMN is a valuable tool for evaluating the benefits of hearing aid features on speech-in-noise processing.