Adaptive feedback cancelling in subbands for hearing aids

In this paper a hearing aid concept with recruitment of loudness compensation and acoustic feedback cancellation is presented. Special consideration is given to the acoustic feedback canceler which uses only the available (e.g. speech) input signal for adaptation. In principle, the feedback canceler is adapted to the feedback path in the transform domain using a power-normalized least mean square (LMS) algorithm. The transformation into uniform subbands is based on an augmentation of the modulated lapped transform (MLT). Together with the hearing-loss compensating forward lter the proposed feedback canceler is computationally very e cient.