Acoustic echo canceller
AssigneeConexant Systems, Inc.
InventorsBryan J. Burns, Yair Kerner, Eitan David
Life of this patent
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Abstract
Disclosed methods and systems measure acoustic responses to training signals activated prior to communication sessions. Profiles related to the acoustic responses are saved and adapted during communication sessions. Training signals may have uniform frequency distributions over a frequency range and may be in response to user inputs, timeouts, or predetermined events. In the next excessive divergence is detected, an adapted profile may be substituted by an original, trained profile.
Claims19
A method for acoustic echo cancellation comprising:
- measuring a first acoustic response from a training signal introduced within an environment, wherein the training signal has a frequency distribution that is substantially uniform across a predetermined frequency range;
- saving a trained profile that is based on the measured first acoustic response;
- accessing the trained profile prior to establishing a session;
- generating an acoustic echo cancellation profile using the trained profile;
- determining whether a threshold level of divergence has occurred between an adapted profile and the trained profile during the communication session;
- and
- resetting the adapted profile to the trained profile in response to detecting the threshold level of divergence.
An acoustic echo canceller comprising:
- a training activator for initiating an audible training signal and for storing a trained profile based on a first response from an environment to the training signal;
- an adaptive filter for using the trained profile to subtract an estimated echo from a speech signal to result in a filtered speech signal, wherein the adaptive filter is further for developing a relined profile based on further responses from the environment to the filtered speech signal;
- and
- a divergence detector for detecting a level of divergence between the refined profile and the trained profile, wherein in response to detecting a threshold level of divergence, the trained profile is reinstated for future subtracting of estimated echo to result in the filtered speech signal.
An acoustic echo cancellation system comprising:
- means for activating a training sequence prior to a user requesting a communication session from a full duplex communication system, wherein the training sequence includes machine-generated audio signals;
- a detector for measuring an acoustic response to the training sequence from a portion of the full duplex communication system, wherein the first acoustic response is used in creating a trained profile, wherein the detector is further used for measuring further acoustic responses from the full duplex communication system to the speaker signal, wherein an adapted profile is created based on the trained profile and is reiteratively modified based at least in part on the further acoustic response estimations;
- and
- a divergence detector for determining whether a threshold level of divergence has occurred between the adapted profile and the trained profile during the communication session;
- wherein the adapted profile is reset to the trained profile in response to detecting the threshold level of divergence.
Dependencies are inferred from the claim text.