Microphone arrays for hearing aids: An overview

Using the difference in the spatial domain (direction or location) between a target signal and noise, a system with a microphone array can achieve the goal of noise reduction and speech enhancement in various environments, especially, in speech-like noisy environments. This paper deals with various issues related to the use of microphone arrays in hearing aids. It includes overall principles, algorithms, real-time implementation, configuration, processing mode, geometry, combination with binaural processing, directivity pattern, frequency responses, and compensation for mismatch and misplacement of microphones. A practical microphone array device will be presented that uses microphone array based processing techniques to help hearing aids deliver improvement in signal-to-noise ratio, reduction of the effects of reverberation, and reduction of the feedback, with appropriate configuration and connections. (C) 2002 Elsevier Science B.V. All rights reserved.