Adaptive acoustic echo cancellation

A system for canceling an estimated echo, comprising:

• a general purpose computing device;
• a computer program comprising program modules executable by the general purpose computing device, wherein the computing device is directed by the program modules of the computer program to,
• input a playback signal into a first linear transform module which converts the playback signal which is originally in the time domain, into the frequency domain;
• input a capture signal into a second linear transform module which converts the capture signal which is originally in the time domain, into the frequency domain;
• input the converted playback signal and the converted capture data in the frequency domain simultaneously into each of a plurality of adaptive acoustic echo cancellation filters, which use different adaptation techniques, and output corresponding resulting fast adaptation and smooth adaptation echo cancelled signals in the frequency domain;
• for each frequency, compute a linear combination of the resulting echo cancelled signals in the frequency domain in a linear combination module;
• compute processed near-end speech with an echo cancelled by combining the linear combinations for each frequency in an inverse transform module.

A system for canceling an acoustic echo, comprising:

• a general purpose computing device;
• a computer program comprising program modules executable by the general purpose computing device, wherein the computing device is directed by the program modules of the computer program to,
• (a) receive a captured data signal and a corresponding playback data signal in the frequency domain;
• (b) for the upper frequency bands of the capture data signal and playback data signal,
• compute a fast adaptation acoustic echo cancellation output for the upper frequency bands;
• choose the fast adaptation acoustic echo cancellation output as the final acoustic echo cancellation output for the upper frequency bands;
• and
• (c) for the lower frequency bands of the capture data signal and playback data signal,
• compute a fast adaptation acoustic echo cancellation output;
• compute a smooth adaptation acoustic echo cancellation output using a momentum normalized least mean squares procedure (MNLMS);
• use a conversion detector to determine if the smooth adaptation acoustic echo cancellation output has converged;
• if the smooth adaptation acoustic echo cancellation output has converged choose the smooth adaptation acoustic echo cancellation output for the final acoustic echo cancellation output for the lower frequency bands;
• if the smooth adaptation acoustic echo cancellation output has not converged choose the fast adaptation acoustic echo cancellation output for the final acoustic echo cancellation output for the lower frequency bands;
• and
• (d) combine the final acoustic echo cancellation output for the high frequency bands with the final acoustic echo cancellation output for the low frequency bands to create a total final acoustic echo cancellation output for both the upper and lower frequency bands.