Adaptive echo cancellation

摘要

An audio-based system may perform echo cancellation using first and second adaptive filters. An adaptation controller may be configured to control whether and/or how the filter coefficients of the first adaptive filter are updated, based on detected filter divergence, echo path changes, and/or presence of near-end user voice. The parameters of the second adaptive filter may be copied from the first adaptive filter under certain conditions that indicate whether copying the parameters would be likely to improve echo suppression.

主权项

1. A system, comprising:
a speaker; a microphone that captures sound from an environment including the speaker and generates an input audio signal; a first adaptive filter configured to dynamically update a plurality of first filter parameters and to produce a first estimated echo signal representing an echo component of an input audio signal, wherein the echo component is a result of audio propagating over one or more echo paths between the speaker and the microphone; an adaptation controller configured to:
reset the first filter parameters to default;determine that the first adaptive filter is converging;determine that the one or more echo paths are stable;determine that a near-end user voice is detected in the input audio signal;stop the dynamically updating of the first filter; a second adaptive filter configured to
receive the first filter parameters from the first adaptive filter, andproduce a second estimated echo signal representing the echo component of the input audio signal based at least in part on the first filter parameters;an echo path change detection component configured to detect a change in the one or more echo paths based, at least in part, on one or more of a change in position of a user relative to the microphone, or a change in position of the speaker; a parameter update controller configured to update second filter parameters from the first filter parameters under one or more specified conditions, wherein at least one of the one or more specified conditions is based, at least in part, on the change in the one or more echo paths; and a subtraction component configured to subtract the second estimated echo signal from the input audio signal to produce an echo-suppressed audio signal.