Evaluation of different pre-whitening decorrelation based adaptive feedback cancellers in hearing aids using perceptual criteria

This paper proposes a perceptual comparative evaluation of some Adaptive Feedback Cancellation (AFC) methods based on decorrelating prefilters. Our objective is to identify suitable AFC methods which give the lowest audible degradation of the amplified speech. Hence, some perceptual criteria measuring only the audible part of the degradation are defined. We show that for hearing impaired subjects who suffer from moderate and severe hearing loss, the perceived distortions and oscillations are lower quantities, compared to the total degradation commonly measured using classical criteria. Moreover, the results of the comparative evaluation of some existing decorrelation methods show that a novel proposed approach based on the reduction of both auto-correlation and intercorrelation between signals (BRP-IVM-AFC) provide the best auditive quality for moderate hearing loss and that the method based on frequency bands reduction (bandlimited-AFC) provides an improvement of the perceived auditive quality for severe hearing loss.