Patent ID: 6072884
Filing Date: 2000-06-06
Classification: H04R

Abstract:
A hearing aid comprising:a microphone for converting sound into an audio signal;feedback cancellation means including means for estimating a physical feedback signal of the hearing aid, and means for modelling a signal processing feedback signal to compensate for the estimated physical feedback signal;subtracting means, connected to the output of the microphone and the output of the feedback cancellation means, for subtracting the signal processing feedback signal from the audio signal to form a compensated audio signal;hearing aid processing means, connected to the output of the subtracting means, for processing the compensated audio signal; andspeaker means, connected to the output of the hearing aid processing means, for converting the processed compensated audio signal into a sound signal;wherein said feedback cancellation means forms a feedback path from the output of the hearing aid processing means to the input of the subtracting means and includesa first filter for modeling near constant factors in the physical feedback path, anda second, quickly varying, filter for modeling variable factors in the feedback path;wherein the first filter varies substantially slower than the second filter.