An adaptive microphone array with good sound quality using auxiliary fixed beamformers and its DSP implementation

Abstract

This paper presents an adaptive microphone array using two auxiliary fixed beamformers for good sound quality. One auxiliary fixed beamformer is introduced in the target signal path to avoid suppression of high-frequency components in the total output. The other auxiliary fixed beamformer is used for adaptation-mode control to eliminate the hysteresis in the relationship between the signal direction and sensitivity. Both auxiliary fixed beamformers bring about good sound quality, which improve intelligibility in speech communications and speech recognition rate. The proposed microphone array is implemented on a DSP system, which demonstrates flat frequency response and less hysteresis in its directivity pattern.