Better speech perception in noise with an assistive multimicrophone array for hearing AIDS

Area of Science:

• Audiology
• Acoustics
• Signal Processing

Background:

• Hearing aids often struggle to improve speech intelligibility in noisy environments.
• Directional microphones and noise reduction algorithms offer limited benefits.
• Assistive listening devices aim to enhance auditory perception in complex soundscapes.

Purpose of the Study:

• To assess the effectiveness of a real-time fixed endfire array of bidirectional microphones.
• To compare the array's performance against a standard omnidirectional hearing aid microphone.
• To evaluate speech intelligibility improvements in realistic noise conditions.

Main Methods:

• The microphone array was physically evaluated in anechoic and reverberant conditions.
• Perceptual tests measured speech reception thresholds in various noise scenarios (two noise types, six scenarios).
• Ten normal-hearing and 10 hearing-impaired listeners participated, using the hearing aid with the array (one, three, or five active microphones).

Main Results:

• The array provided significant speech intelligibility improvements over an omnidirectional microphone.
• With three active microphones, improvements reached up to 12 dB (normal-hearing) and 9 dB (hearing-impaired) with a single noise source.
• Even with multiple noise sources or single sources at different angles, substantial benefits (4-9 dB) were observed for both groups.

Conclusions:

• The assistive microphone array offers considerable improvements in signal-to-noise ratio.
• These enhancements can greatly benefit hearing aid users experiencing difficulties in noisy environments.
• The fixed endfire array represents a promising assistive technology for improving auditory accessibility.