Abstract

A multi microphone array technique for hearing aid noise reduction is described. This study evaluates a spatial-filtering algorithm as a method to improve speech reception for monaural and binaural hearing impaired users in reverberant environments with multiple noise sources. The system has to filter sounds using phase differences between two microphones situated some distance apart in a behind-the-ear hearing-aid capsule. The approach is to linearly combine microphone signals after amplitude scaling and phase shifting. This approach is linear and time-invariant and can be used to generate known directional responses. Such approaches are generally referred to as beamforming algorithms. Beamformers can be implemented in analog, multiport, microphone circuitry to produce directional microphones. These techniques help to filter sounds using phase differences between microphones and provide improvements in speech signal across listening conditions compared with the omnidirectional response also spatial filtering can improve speech reception for hearing impaired users even in highly reverberant conditions with multiple noise sources.