Patent ID: 9578426
Date: 2017-02-21
CPC Classifications: H04R

Claim:
1. A method for feedback cancelling in a hearing device comprising at least one microphone, an analysis filter bank, a gain unit, a synthesis filter bank, a receiver and a feedback canceller comprising a first adaptive filter and a cross filter, the method comprising: the at least one microphone providing at least one microphone signal; the analysis filter bank decomposing the at least one microphone signal into a first plurality of sub-band signals; the gain unit applying a frequency-dependent gain to the first plurality of sub-band signals and providing a first plurality of amplified sub-band signals; the synthesis filter bank converting the first plurality of amplified sub-band signals into a receiver input signal; and the receiver outputting a sound signal dependent on the receiver input signal, characterised in the first adaptive filter providing a second plurality of feedback compensation signals adapted to compensate acoustic feedback from the receiver to the at least one microphone, and subtracting the second plurality of feedback compensation signals from corresponding signals from the first plurality of sub-band signals to provide a first plurality of feedback compensated sub-band signals; the cross filter estimating a third plurality of cross-frequency signal components resulting from aliasing of signal components from one sub-band into one or more neighbouring sub-bands caused by non-ideal sub-band signal decomposition in the analysis filter bank with overlapping sub-bands; and adapting the first adaptive filter in dependence of a difference between the first plurality of feedback compensated sub-band signals and corresponding components from the third plurality of estimated cross-frequency signal components.