Patent ID: 8655001
Filing Date: 2014-02-18
Classification: H04R

Abstract:
1. A hearing aid comprising: a sound producing transducer configured for mounting in a user's ear canal; a first sound responsive transducer configured for mounting in said user's ear canal, said first sound responsive transducer being further configured to detect sound and produce a first output signal based on said detected sound; hearing aid electronics responsive to said output signal provided by said first sound responsive transducer for driving said sound producing transducer; feedback cancellation circuitry including an adaptive digital filter that uses multiple filter coefficients to produce for producing a feedback signal; a second sound responsive transducer configured for mounting in said user's ear canal, said second sound responsive transducer being further configured to detect said sound and produce a second output signal based on said detected sound; an acoustic feedback path processor responsive to respective output signals provided by said first and second sound responsive transducers and configured to use said first and second output signals to detect a change in an impedance of an acoustic feedback path coupling said sound producing transducer to said sound responsive transducers; and an adaptation controller configured to control an adaptation speed of said adaptive digital filter based on said detected change in said impedance of said acoustic feedback path by modifying at least one of said filter coefficients in response to said detected change in said impedance of said acoustic feedback path.