Patent ID: 6876751
Filing Date: 2005-04-05
Classification: H03H,H04R

Abstract:
1. A feedback canceller for an audio amplification device comprising: an adaptive filter comprising means for convolving? an input of the adaptive filter with filter coefficients; means for combining an output of the adaptive filter with an input of the audio amplification device; a first band limiting filter having an input coupled to an output of the audio amplification device and an output coupled to the input of the adaptive filter, wherein the first band limiting filter has a passband limited to a frequency band containing unstable frequencies; a second band limiting filter having an input coupled to the input of the audio amplification device and an output; a third band limiting filter having an input coupled to the output of the first band limiting filter and an output; wherein the second and third band limiting filters have passbands limited to the frequency band containing unstable frequencies and the filter coefficients are functions of the outputs of the second and third band limiting filters.