Noise suppression method and system for personal sound amplification product

1. A method of noise suppression for a personal sound amplification product (PSAP), comprising:

processing an environmental audio signal acquired through one or more microphones to generate a set of first sub-band signals in a set of first sub-bands;

processing the environmental audio signal to generate a set of second sub-band signals in a set of second sub-bands;

determining a set of first gains for the set of first sub-band signals in the set of first sub-bands based on the set of second sub-band signals in the set of second sub-bands; and

processing the set of first sub-band signals based on the set of first gains to generate a noise-suppressed audio signal,

wherein determining the set of first gains comprises:

determining a set of speech presence probabilities associated with the set of second sub-band signals, respectively;

determining a set of second gains in the set of second sub-bands based on the set of speech presence probabilities, respectively; and

determining the set of first gains in the set of first sub-bands based on the set of second gains in the set of second sub-bands:

wherein the set of speech presence probabilities comprises a set of posterior speech presence probabilities associated with the set of second sub-band signals; and

wherein determining the set of speech presence probabilities associated with the set of second sub-band signals, respectively, comprises:

for each second sub-band signal in a corresponding second sub-band,

determining a prior speech presence probability and a prior signal-to-noise ratio (SNR) associated with the second sub-band signal;

determining an intermediate variable determined based on the prior speech presence probability and the prior SNR; and

determining a posterior speech presence probability associated with the second sub-hand signal based on the prior speech presence probability, the prior SNR, and the intermediate variable.

2. The method of claim 1 , wherein determining the set of first gains in the set of first sub-bands based on the set of second gains in the set of second sub-bands comprises:

for each first sub-band,

determining, from the set of second sub-bands, one or more second sub-bands included within the first sub-band;

determining, from the set of second gains, one or more second gains in the one or more second sub-bands, respectively; and

determining a first gain in the first sub-band based on the one or more second gains.

3. The method of claim 2 , wherein determining the first gain in the first sub-band based on the one or more second gains comprises:

determining the first gain in the first sub-band from the one or more second gains further based on a level of wind noise.

4. The method of claim 3 , further comprising:

determining a composite wind noise indicator associated with the wind noise; and

determining the level of the wind noise based on the composite wind noise indicator.

5. The method of claim 4 , wherein:

the environmental audio signal comprises a first audio signal acquired by a first microphone and a second audio signal acquired by a second microphone; and

determining the composite wind noise indicator associated with the wind noise comprises:

determining a relevance factor between the first and second audio signals; and

responsive to the relevance factor being below a relevance threshold,

estimating an energy factor based on the first and second audio signals; and

determining the composite wind noise indicator based on the relevance factor and the energy factor.

6. The method of claim 5 , wherein determining the relevance factor between the first and second audio signals comprises:

determining a first energy parameter associated with the first audio signal;

determining a second energy parameter associated with the second audio signal; and

determining the relevance factor based on the first and second energy parameters.

7. The method of claim 5 , wherein estimating the energy factor based on the first and second audio signals comprises:

estimating a wind energy based on the first and second audio signals; and

estimating the energy factor based on the wind energy.

8. The method of claim 3 , wherein determining the first gain in the first sub-band from the one or more second gains further based on the level of the wind noise comprises:

responsive to the first sub-band being smaller than a frequency threshold and the level of the wind noise being smaller than or equal to a level threshold, determining the first gain to be a maximal gain among the one or more second gains;

responsive to the first sub-band being smaller than or equal to the frequency threshold and the level of the wind noise being greater than the level threshold, determining the first gain to be a minimal gain among the one or more second gains; or

responsive to the first sub-band being equal to or greater than the frequency threshold, determining the first gain to be one.

9. The method of claim 1 , further comprising:

determining a wind noise suppression factor based on a level of wind noise; and

adjusting the set of first gains based on the wind noise suppression factor.

10. A personal sound amplification product (HAP), comprising:

one or more microphones configured to acquire an environmental audio signal;

a first filter set configured to process the environmental audio signal to generate a set of first sub-band signals in a set of first sub-bands;

a second filter set configured to process the environmental audio signal to generate a set of second sub-band signals in a set of second sub-bands;

a processor configured to determine a set of first gains for the set of first sub-band signals in the set of first sub-bands based on the set of second sub-band signals in the set of second sub-bands;

a set of gain control units configured to process the set of first sub-band signals based on the set of first gains, respectively; and

a third filter set configured to synthesize the set of first sub-band signals to generate a noise-suppressed audio signal,

wherein to determine the set of first gains, the processor is further configured to:

determine a set of speech presence probabilities associated with the set of second sub-band signals, respectively;

determine a set of second gains in the set of second sub-bands based on the set of speech presence probabilities, respectively; and

determine the set of first gains in the set of first sub-bands based on the set of second gains in the set of second sub-bands;

wherein the set of speech presence probabilities comprises a set of posterior speech presence probabilities associated with the set of second sub-band signals; and

wherein to determine the set of speech presence probabilities associated with the set of second sub-band signals, respectively, the processor is further configured to:

for each second sub-band signal in a corresponding second sub-band,

determine a prior speech presence probability and a prior signal-to-noise ratio (SNR) associated with the second sub-band signal;

determine an intermediate variable determined based on the prior speech presence probability and the prior SNR; and

determine a posterior speech presence probability associated with the second sub-band signal based on the prior speech presence probability, the prior SNR, and the intermediate variable.

11. The PSAP of claim 10 , wherein to determine the set of first gains in the set of first sub-bands based on the set of second gains in the set of second sub-bands, the processor is further configured to:

for each first sub-band,

determine, from the set of second sub-bands, one or more second sub-bands included within the first sub-band;

determine, from the set of second gains, one or more second gains in the one or more second sub-bands, respectively; and

determine a first gain in the first sub-band based on the one or more second gains.

12. The PSAP of claim 11 , wherein to determine the first gain in the first sub-band based on the one or more second gains, the processor is further configured to:

determine the first gain in the first sub-band from the one or more second gains further based on a level of wind noise.

13. The PSAP of claim 12 , wherein

the one or more microphones comprise a first microphone and a second microphone;

the environmental audio signal comprises a first audio signal acquired by the first microphone and a second audio signal acquired by the second microphone;

the processor is further configured to:

determine a relevance factor between the first and second audio signals;

estimate an energy factor based on the first and second audio signals;

determine a composite wind noise indicator based on the relevance factor and the energy factor; and

determine the level of the wind noise based on the composite wind noise indicator.

14. The PSAP of claim 10 , wherein to determine the set of first gains in the set of first sub-bands based on the set of second gains in the set of second sub-bands comprises, the processor is further configured to:

for each first sub-band,

determine, from the set of second sub-bands, one or more second sub-bands included within the first sub-band;

determine, from the set of second gains, one or more second gains in the one or more second sub-bands, respectively; and

determine a first gain in the first sub-band based on the one or more second gains.

15. The PSAP of claim 14 , wherein to determine the first gain in the first sub-band based on the one or more second gains, the processor is further configured to:

determine the first gain in the first sub-band from the one or more second gains further based on a level of wind noise.

16. The PSAP of claim 15 , wherein the processor is further configured to:

determine a composite wind noise indicator associated with the wind noise; and

determine the level of the wind noise based on the composite wind noise indicator.

17. A system of noise suppression for a personal sound amplification product (PSAP), comprising:

a memory storing code; and

a processor coupled to the memory, wherein when the code is executed, the processor is configured to:

receive a set of first sub-band signals in a set of first sub-bands, wherein the set of first sub-band signals is generated from an environmental audio signal acquired through one or more microphones;

receive a set of second sub-band signals in a set of second sub-bands, wherein the set of second sub-band signals is also generated from the environmental audio signal;

determine a set of first gains for the set of first sub-band signals in the set of first sub-bands based on the set of second sub-band signals in the set of second sub-bands; and

provide the set of first gains to process the set of first sub-band signals so that a noise-suppressed audio signal is generated from the set of first sub-band signals,

wherein to determine the set of first gains, the processor is further configured to:

determine a set of speech presence probabilities associated with the set of second sub-band signals, respectively;

determine a set of second gains in the set of second sub-bands based on the set of speech presence probabilities, respectively; and

determine the set of first gains in the set of first sub-bands based on the set of second gains in the set of second sub-bands;

wherein to determine the set of first gains in the set of first sub-bands based on the set of second gains in the set of second sub-bands, the processor is further configured to:

for each first sub-band,

determine, from the set of second sub-bands, one or more second sub-bands included within the first sub-band;

determine, from the set of second gains, one or more second gains in the one or more second sub-bands, respectively; and

determine a first gain in the first sub-band based on the one or more second gains; and

wherein to determine the first gain in the first sub-band based on the one or more second gains, the processor is further configured to:

determine the first gain to be a maximal gain among the one or more second gains.

18. A method of noise suppression for a personal sound amplification product (PSAP), comprising:

processing an environmental audio signal acquired through one or more microphones to generate a set of first sub-band signals in a set of first sub-bands;

processing the environmental audio signal to generate a set of second sub-band signals a set of second sub-bands;

determining a set of first gains for the set of first sub-band signals in the set of first sub-bands based on the set of second sub-band signals in the set of second sub-bands; and

processing the set of first sub-band signals based on the set of first gains to generate a noise-suppressed audio signal,

wherein determining the set of first gains comprises:

determining a set of speech presence probabilities associated with the set of second sub-band signals, respectively;

determining a set of second gains in the set of second sub-bands based on the set of speech presence probabilities, respectively; and

determining the set of first gains in the set of first sub-bands based on the set of second gains in the set of second sub-bands;

wherein determining the set of first gains in the set of first sub-bands based on the set of second gains in the set of second sub-bands comprises:

for each first sub-band,

determining, from the set of second sub-bands, one or more second sub-bands included within the first sub-band;

determining, from the set of second gains, one or more second gains in the one or more second sub-bands, respectively; and

determining a first gain in the first sub-band based on the one or more second gains; and

wherein determining the first gain in the first sub-band based on the one or more second gains comprises:

determining the first gain to be a maximal gain among the one or more second gains.

19. The method of claim 18 , wherein the set of speech presence probabilities comprises a set of posterior speech presence probabilities associated with the set of second sub-band signals.

20. The method of claim 19 , wherein determining the set of speech presence probabilities associated with the set of second sub-band signals, respectively, comprises:

for each second sub-band signal in a corresponding second sub-band,

determining a prior speech presence probability and a prior signal-to-noise ratio (SNR) associated with the second sub-band signal;

determining an intermediate variable determined based on the prior speech presence probability and the prior SNR; and

determining a posterior speech presence probability associated with the second sub-band signal based on the prior speech presence probability, the prior SNR, and the intermediate variable.