An evaluation of three adaptive hearing aid selection strategies

Area of Science:

• Audiology
• Hearing Science
• Speech Processing

Background:

• Hearing aids are crucial for individuals with hearing impairments.
• Optimizing hearing aid settings, specifically frequency-gain characteristics, is essential for improving speech intelligibility in noisy environments.
• Various adaptive strategies exist to determine these optimal settings.

Purpose of the Study:

• To compare the efficiency and convergence of three adaptive strategies for determining optimal hearing aid frequency-gain characteristics.
• To evaluate the impact of different hearing aid frequency-gain configurations on speech intelligibility in noise for hearing-impaired subjects.

Main Methods:

• Paired-comparison judgments of speech intelligibility in noise were collected from eight hearing-impaired subjects.
• A digital master hearing aid simulated various hearing aid configurations (5x5 matrix) with systematic variations in low- and high-frequency gain.
• Three adaptive strategies were compared: iterative round robin, double elimination tournament, and modified simplex procedure.

Main Results:

• Most subjects showed convergence towards the same or similar hearing aids across the three adaptive strategies.
• Subjects whose procedures converged on a single hearing aid exhibited a pronounced peak in the response surface.
• A broader peak was observed for subjects where strategies identified similar, but not identical, hearing aids.
• The modified simplex procedure was the most efficient, while the iterative round robin was the least efficient.

Conclusions:

• Adaptive strategies can effectively identify optimal hearing aid frequency-gain characteristics for hearing-impaired individuals.
• The modified simplex procedure offers an efficient method for this optimization process.
• Understanding the response surface can provide insights into individual subject preferences and hearing aid performance.