Multi-microphone noise cancellation for improvement of hearing aid performance

A scheme for binaural pre-processing of speech signals for input to a standard linear hearing aid has been investigated. The system is based on that of Toner & Campbell (1993) who applied the least mean squares (LMS) algorithm in sub-bands to speech signals from various acoustic environments and signal to noise ratios (SNR). The processing scheme attempts to take advantage of the multiple inputs to perform noise cancellation. The use of sub-bands enables a diverse processing mechanism to be employed, where the wide-band signal is split into smaller frequency limited sub-bands, which can subsequently be processed according to their signal characteristics. The results of a large scale series of intelligibility tests are presented from experiments in which acoustic speech and noise data, generated using simulated and real-room acoustics was tested on hearing impaired volunteers.