An efficient feedback cancellation for multiband compression hearing aids

Maximum usable gain of hearing aids is seriously limited by the acoustic feedback which is persistent and often annoying to hearing aid users. The adaptive feedback cancellation is known to be an effective way of reducing the acoustic feedback where the acoustic environment varies significantly. In this paper, we propose a multiband adaptive feedback cancellation scheme. The proposed scheme estimates the feedback path only for selected frequency bands in which the feedback is most likely occur. Thus, the feedback is prevented by increasing the maximum usable gain in these bands only. This scheme is very useful for multiband hearing aids because typically more gains are required in certain bands than others. Simulation results show that the increase of the maximum usable gain ranges 1~7.5 dB over the conventional method in selected frequency bands