A real time implementation and an evaluation of an optimal filtering technique for noise reduction in dual microphone hearing aids

A real time implementation and an evaluation of a singular value decomposition (SVD) based optimal filtering technique (Doclo, S. and Moonen, M., IEEE Trans. Sig. Process., vol.50, no.9, p.2230-44, 2002) for noise reduction in a dual microphone BTE (behind-the-ear) hearing aid is presented. A method to improve the performance of a voice activity detector (VAD) is described and evaluated physically. This method is used in the real time implementation of the optimal filtering technique. A perceptual evaluation by normal hearing subjects is carried out for single and multiple jammer sound sources with speech weighted noise. The SVD-based technique can perform as well as an adaptive beamformer strategy (Maj, J.B. et al., Ear and Hearing, 2003) in a single noise scenario (i.e. the ideal scenario for the latter technique), and, can outperform the beamformer technique in a multiple noise sources scenario.