Signal enhancement and noise reduction with binaural cue preservation control based on interaural coherence

1. A method, comprising, by one or more processors:

detecting, via an acoustic sensor array, sounds from a local area;

determining an interaural coherence using the detected sounds;

determining a parameter μ that controls a tradeoff between signal-to-noise ratio (SNR) and sound distortion;

determining a parameter η that controls preserving of binaural information of an interfering source based on the interaural coherence;

generating sound filters for an audio signal based on the parameters μ and η, the sound filters implementing a tradeoff between increasing the SNR between a target source and the interfering source and preserving of the binaural information of the interfering source, tradeoff being controlled based on the interaural coherence;

applying the sound filters to the audio signal to generate audio content; and

presenting, via a speaker array, the audio content.

2. The method of claim 1 , wherein the sound filters each includes a binaural multichannel Wiener filter with noise estimation.

3. The method of claim 1 , further comprising, by the one or more processors:

responsive to the interaural coherence being less than a threshold value, setting the parameter μ such that the sound filters include a binaural minimum-variance distortion-less response; and

responsive to interaural coherence being greater than the threshold value, setting the parameter μ as a function of tolerated sound distortion.

4. The method of claim 1 , further comprising, by the one or more processors, determining η based on a first interaural time difference (ITD) of the target source, a first ITD just noticeable difference (JND) of the target source, a second ITD of the interfering source, and a second ITD JND of the interfering source.

5. The method of claim 4 , wherein determining η comprises:

determining, for the interaural coherence, an ITD difference between the first ITD and the second ITD;

determining a maximum ITD JND of the first ITD JND and the second ITD JND; and

responsive to the ITD difference being less than the maximum ITD JND, setting η to maximize increasing SNR and minimize preserving of the binaural information of the interfering source.

6. The method of claim 4 , wherein determining η includes:

determining, for the interaural coherence, an ITD difference between first ITD and the second ITD;

determining a maximum ITD JND of the first ITD JND and the second ITD JND; and

responsive to the ITD difference being greater than the maximum ITD JND, setting η based on:

determining an angular separation between a first direction of arrival (DOA) of the target source and a second DOA of the interfering source;

determining a binaural release from masking (BRFM) of the target and interfering sources based on the angular separation; and

determining such that, for the interaural coherence, a sum of an expected SNR for η and the BRFM is within 3 dB of a baseline SNR.

7. The method of claim 6 , wherein the baseline SNR is 0 dB and the sum of the expected SNR and η is equal to the baseline SNR.

8. The method of claim 1 , wherein the interaural coherence is determined using a subband of the detected sounds and the sound filters are applied to the subband of the audio signal.

9. A device, comprising:

an acoustic sensor array configured to detect sounds from a local area;

a speaker array;

one or more processors; and

a memory storing program code that, when executed by the one or more processors, configures the one or more processors to:

determine an interaural coherence using the detected sounds;

determine a parameter μ that controls a tradeoff between signal-to-ratio (SNR) and sound distortion;

determine a parameter η that controls preserving of binaural information of an interfering source based on an interaural coherence;

generate sound filters for an audio signal based in part on the parameters μ and η, the sound filters implementing a tradeoff between increasing the SNR between a target source and the interfering source and preserving of the binaural information of the interfering source, tradeoff being controlled based on the interaural coherence;

apply the sound filters to the audio signal to generate audio content; and

present, via the speaker array, the audio content.

10. The device of claim 9 , wherein the sound filters each includes a binaural multichannel Wiener filter with noise estimation.

11. The device of claim 9 , wherein the program code further configures the one or more processors for:

responsive to the interaural coherence being less than a threshold value, setting the parameter μ such that the sound filters include a binaural minimum-variance distortion-less response; and

responsive to interaural coherence being greater than the threshold value, setting the parameter μ as a function of tolerated sound distortion.

12. The device of claim 9 , wherein the program code further configures the one or more processors for, determining η based on:

determining, for the interaural coherence, an interaural time difference (ITD) difference between a first ITD of the target source and a second ITD of the interfering source;

determining a maximum ITD just noticeable difference (JND) of a first ITD JND of the target source and a second ITD JND of the interfering source; and

responsive to the ITD difference being less than the maximum ITD JND, setting η to maximize increasing SNR and minimize preserving of the binaural information of the interfering source.

13. The device of claim 9 , wherein the program code further configures the one or more processors for, determining η based on:

determining, for the interaural coherence, an interaural time difference (ITD) difference between a first ITD of the target source and a second ITD of the interfering source;

determining a maximum ITD just noticeable difference (JND) of a first ITD JND of the target source and a second ITD JND of the interfering source; and

responsive to the ITD difference being less than the maximum ITD JND, setting η based on:

determining an angular separation between a first direction of arrival (DOA) of the target source and a second DOA of the interfering source;

determining a binaural release from masking (BRFM) of the target and interfering sources based on the angular separation; and

determining such that, for the interaural coherence, a sum of an expected SNR for η and the BRFM is within 3 dB of a baseline SNR.

14. The device of claim 13 , wherein the baseline SNR is 0 dB and the sum of the expected SNR and η is equal to the baseline SNR.

15. The device of claim 9 , wherein the interaural coherence is determined using a subband of the detected sounds and the sound filters are applied to the subband of the audio signal.

16. A non-transitory computer-readable storage medium comprising stored program code that, when executed by one or more processors of an audio system, causes the audio system to:

detect, via an acoustic sensor array, sounds from a local area;

determine an interaural coherence using the detected sounds;

determine a parameter μ that controls a tradeoff between signal-to-noise ratio (SNR) and sound distortion;

determine a parameter η that controls preserving of binaural information of an interfering source based on the interaural coherence;

generate sound filters for an audio signal based on the parameters μ and η, the sound filters implementing a tradeoff between increasing the SNR between a target source and the interfering source and preserving of the binaural information of the interfering source, tradeoff being controlled based on the interaural coherence;

apply the sound filters to the audio signal to generate audio content; and

present, via a speaker array, the audio content.

17. The non-transitory computer-readable storage medium of claim 16 , wherein the sound filters each includes a binaural multichannel Wiener filter with noise estimation.

18. The non-transitory computer-readable storage medium of claim 16 , further comprising stored program code that, when executed by one or more processors of an audio system, causes the audio system to:

responsive to the interaural coherence being less than a threshold value, set the parameter μ such that the sound filters include a binaural minimum-variance distortion-less response; and

responsive to interaural coherence being greater than the threshold value, set the parameter μ as a function of tolerated sound distortion.

19. The non-transitory computer-readable storage medium of claim 16 , further comprising stored program code that, when executed by one or more processors of an audio system, causes the audio system to:

determine η based on a first interaural time difference (ITD) of the target source, a first ITD just noticeable difference (JND) of the target source, a second ITD of the interfering source, and a second ITD JND of the interfering source.

20. The non-transitory computer-readable storage medium of claim 19 , further comprising stored program code that, when executed by one or more processors of an audio system, causes the audio system to:

determine, for the interaural coherence, an ITD difference between the first ITD and the second ITD;

determine a maximum ITD JND of the first ITD JND and the second ITD JND; and

responsive to the ITD difference being less than the maximum ITD JND, set η to maximize increasing SNR and minimize preserving of the binaural information of the interfering source.