Robust foreground/background filtering control for acoustic echo cancellation

Abstract

Systems and methods are described for controlling adaptive filtering components. A far end signal may be filtered by each of a foreground filter and a background filter, where both filters are adaptive echo cancellation filters that output echo estimations. Control logic may halt adaptation by the background filter based on a deviation signal. To determine the deviation signal, cross-correlation coefficients for the echo estimations produced by both filters may be determined for each frequency bin of the far end signal. The determined cross-correlation coefficients may be summed across a plurality of the frequency bins. A hysteresis function may then be applied to the sum associated with the filter associated with the echo estimation used to generate a filtered result. The deviation signal may be activated in response to the hysteresis function outputting a high value, which the control logic uses to turn off adaptation by the background filter.