A system for canceling acoustic feedback includes an input for receiving a
digital audio signal and a processor configured to detect acoustic
feedback signal in the digital audio signal and to determine the
frequency of the feedback signal The system also includes a plurality of
bandpass filters for attenuating the feedback signal. The processor is
further configured to: select a bandpass filter from among the plurality
of bandpass filters. The selected bandpass filter comprises a response
characteristic that attenuates parts of the signal at the frequency of
acoustic feedback signal.