Microphone array for hearing aid and speech enhancement applications

Microphone array technology has been proposed for various audio, teleconference, hearing aid and voice recognition applications. By forming a focused beam toward the desired speech source, attenuating background noises and rejecting discrete spatial interferers, a microphone array can enhance the signal-to-noise-ratio (SNR) in a noisy environment with notable improvement in speech intelligibility. At the threshold of intelligibility, a one dB improvement in SNR can increase 10-15% speech intelligibility. It is also known that increasing SNR can result in significant improvement in the recognition rate of various automatic voice recognition systems. We propose a novel electronically steerable microphone array based on the maximum energy (ME) concentration criterion, which results in high SNR in rooms with reverberations and competing interferences. We present a prototype PC-based microphone array system designed for hearing aid applications but also applicable to other tasks