Patent ID: 8611572
Filing Date: 2013-12-17
Classification: H04R

Abstract:
1. A device for controlling a step size of an adaptive filter for suppressing an acoustic feedback, comprising: an analyzing unit that analyzes an input signal in a plurality of frequency bands and detects steep signal edges in an individual frequency band of the plurality of frequency bands having rates of rise exceeding a predetermined rate in the individual frequency band; and a control unit connected to the analyzing unit that controls the step size of the adaptive filter based on a number of frequency bands in which the steep signal edges are detected, wherein the step size of the adaptive filter is increased by the control unit if the steep signal edges are detected in a maximum of two frequency bands indicating a presence of the acoustic feedback, wherein the step size of the adaptive filter is reduced by the control unit if the steep signal edges are detected in more than two frequency bands indicating a presence of a transient signal, and wherein the predetermined rate is a standard step size of the individual frequency band.