Patent ID: 6480610
Filing Date: 2002-11-12
Classification: H04R

Abstract:
A method for canceling acoustic feedback in hearing aids, comprising the steps of:digitizing an input audio signal into a sequence of digital audio samples; splitting said sequence of digital audio samples into a plurality of subband signals; processing each of said plurality of subband signals separately with a noise reduction and hearing loss compensation algorithm into a plurality of processed digital subband audio signals; combining said plurality of processed digital subband audio signals into a processed wideband digital audio signal; converting said processed wideband digital audio signal into an output audio signal; splitting said processed wideband digital audio signal into a plurality of subband feedback signals; filtering each of said plurality of subband feedback signals with a narrow-band training filter that models the static portion of the feedback path in each of said subbands and provides an output thereof; filtering each said output of said narrow-band training filter with a narrow-band tracking filter that tracks the variations of the feedback path in each of said subbands, and provides an output thereof, and subtracting said output of each of said narrow-band tracking filters from the corresponding subband signal of said plurality of subband signals.