Mitigation of inaccurate echo prediction
Systems and methods are described for compensating for inaccurate echo prediction in audio systems. A signal may be received at a microphone of an audio system, the signal including audio rendered using a spatial audio renderer across a multi-channel audio output. A signal may be received from the spatial audio renderer that indicates a change in rendering of audio. The audio system may then determine if there is echo power within the received signal greater than an expected echo power. After the signal from the spatial audio renderer has been received, the echo suppression applied to the received signal may be modified in response to a determination that the echo power is greater than the expected echo power, the echo suppression attenuating pre-selected frequency bands of the received signal.
1. A method for detecting and compensating for inaccurate echo prediction, the method comprising:
receiving a signal at a microphone of an audio system, the signal including audio rendered using a spatial audio renderer across a multi-channel audio output of the audio system;
determining a predicted echo power value based on the received signal;
suppressing echo in the received signal by attenuating pre-selected frequency bands of the received signal based on the predicted echo power value;
receiving a signal from the spatial audio renderer that indicates a change in rendering of audio; and
modifying the echo suppression, by the audio system after the signal from the spatial audio renderer has been received, applied to the received signal in response to receiving the signal from the spatial audio renderer.
2. The method of claim 1 , the modifying echo suppression comprising at least one of:
forcing adaptation of an echo suppression module that applies the echo suppression to the received signal; and
increasing an adaptation rate of the echo suppression module.
3. The method of claim 1 , the modifying echo suppression comprising scaling the predicted echo power value such that the predicted echo power value is increased.
4. The method of claim 1 , wherein the echo suppression applied to the received signal is further based on a detected echo power value, the modifying echo suppression comprising adjusting the predicted echo power value using predetermined filter coefficients.
5. The method of claim 1 , the signal from the spatial audio renderer further comprising an identification of a change type associated with the change in rendering of audio, the applying echo suppression taking place over a predetermined time interval associated with the identified change type.
6. The method of claim 1 , further comprising applying, by the audio system, echo cancellation to the received signal to generate a residual signal, the echo cancellation comprising subtracting a predicted echo from the received signal, the predicted echo being based on an estimate of an electroacoustic path from speakers of the audio system to the microphone, the echo suppression being applied to the residual signal.
7. The method of claim 6 , further comprising determining, by the audio system, that a non-full rank covariance matrix is being used in the echo cancellation and modifying echo suppression, by the audio system, applied to the received signal in response to the determination that the non-full rank covariance matrix is being used.
8. The method of claim 1 , further comprising receiving an indication of a system event of the audio system and modifying echo suppression, by the audio system, applied to the received signal in response to receiving the indication of the system event.
9. An audio system comprising:
a spatial audio renderer that renders audio across a multi-channel audio output;
a microphone that captures a signal, the signal including the rendered audio;
an adaptive echo suppressor circuit that suppresses echo in the received signal, the echo suppression attenuating pre-selected frequency bands of the received signal based on a predicted echo power value that is determined based on the captured signal; and
a control circuit coupled to the adaptive echo suppressor circuit and the spatial audio renderer, the control circuit receiving a signal from the spatial audio renderer that indicates a change in rendering of audio, and causing the adaptive echo suppressor circuit to modify echo suppression applied to the received signal in response to receiving the signal from the spatial audio renderer, the echo suppression attenuating pre-selected frequency bands of the received signal.
10. The system of claim 9 , the causing the adaptive echo suppressor circuit to modify echo suppression comprising at least one of:
forcing adaptation of the adaptive echo suppressor circuit; and
increasing an adaptation rate of the adaptive echo suppressor circuit.
11. The system of claim 9 , the causing the adaptive echo suppressor circuit to modify echo suppression comprising scaling the predicted echo power value such that the predicted echo power value is increased, and attenuating pre-selected frequency bands of the received signal based on the scaled predicted echo power value.
12. The system of claim 9 , further comprising an echo cancellation circuit communicatively coupled to the control circuit, the echo cancellation circuit receiving the signal from a microphone and applying echo cancellation to the received signal to generate a residual signal, the echo cancellation comprising subtracting a predicted echo from the received signal, the predicted echo being based on an estimate of an electroacoustic path from speakers of the audio system to the microphone, the echo suppression being applied to the residual signal received from the echo cancellation circuit.
13. The system of claim 9 , the signal from the spatial audio renderer further comprising an identification of a change type associated with the change in rendering of audio, the applying echo suppression taking place over a predetermined time interval associated with the identified change type.
14. A method for detecting and compensating for echo cancellation instability, the method comprising:
receiving a signal at a microphone of an audio system, the signal including audio rendered using a spatial audio renderer across a multi-channel audio output of the audio system;
applying, by the audio system, echo cancellation to the received signal to generate a residual signal, the echo cancellation comprising subtracting a predicted echo from the received signal, the predicted echo being based on an estimate of an electroacoustic path from speakers of the audio system to the microphone;
determining a predicted echo power value based on the received signal;
suppressing echo in the residual signal by attenuating pre-selected frequency bands of the residual signal based on the predicted echo power value;
determining, by the audio system, that a non-full rank covariance matrix is being used in determining the predicted echo; and
modifying the echo suppression, by the audio system, applied to the residual signal in response to the determination that the non-full rank covariance matrix is being used.
15. A computer program product having instructions which, when executed by a computing device or system, cause said computing device or system to perform the method according to claim 14 .
16. A data-processing system comprising:
one or more processors; and
a non-transitory computer-readable medium storing instructions that, upon execution by the one or more processors, cause the one or more processors to execute the method according to claim 14 .