Improving speech intelligibility in background noise with an adaptive directional microphone

Area of Science:

• Audiology
• Speech and Hearing Sciences
• Acoustics

Background:

• Hearing aids utilize various microphone technologies to enhance speech perception.
• Adaptive Directional Microphones (ADM) aim to optimize sound capture in complex listening environments.
• The Auditory Dynamic Range Optimization (ADRO) scheme is a hearing aid amplification strategy.

Purpose of the Study:

• To evaluate the effectiveness of Adaptive Directional Microphones (ADM) compared to omnidirectional and supercardioid microphones.
• To assess the performance of ADM in conjunction with the ADRO amplification scheme for individuals with moderate sloping hearing loss.
• To determine user preference and real-world benefit of ADM in hearing aid use.

Main Methods:

• Eight participants with moderate sloping hearing loss were tested.
• Speech perception was measured using the Hearing in Noise Test (HINT) across different noise conditions.
• Subjective feedback on listening experience and microphone preference was collected using the Speech, Spatial and Qualities of Hearing Scale (SSQ).

Main Results:

• Adaptive Directional Microphones (ADM) yielded superior speech perception scores compared to omnidirectional and supercardioid microphones in all tested noise conditions.
• Participants using ADM achieved signal-to-noise ratios (SNR) of -4.5 dB or better, comparable to normal hearing.
• Subjective reports indicated no disadvantage in real-life situations, with a 54% preference for ADM over omnidirectional microphones.

Conclusions:

• The combination of ADM for improved SNR and ADRO for comfortable audibility offers near-normal hearing performance for moderate hearing loss.
• Adaptive Directional Microphones (ADM) are recommended as the optimal microphone configuration for ADRO hearing aids.
• This technology demonstrates significant potential for enhancing audibility and speech intelligibility in challenging acoustic environments.