Multi-channel wind noise suppression system and method

• US 9,357,307 B2
• Filed: 02/07/2012
• Issued: 05/31/2016
• Est. Priority Date: 02/10/2011
• Status: Active Grant

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Inventors: Taenzer, Jon C.
• Primary Examiner(s): Mei, Xu
• Application Number:
  US13/368,100
• Publication Number:
  US 20120207325A1
• Time in Patent Office: 1,575 Days
• Field of Search: 381/92, 381 941- 943, 381/94.7, 381/317, 381/71.1, 381/122, 704/226, 704/228, 704/233, 379/406.01, 379/406.07, 379/392.01, 379/406.03, 379/406.14, 370/2, 370/286
• US Class Current: 1/1
• CPC Class Codes: H04R 2410/05 Noise reduction with a separate noise microphone
• CPC Class Codes: H04R 2410/07 Mechanical or electrical reduction of wind noise generated by wind passing a microphone
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04R 5/04 Circuit arrangements, e.g. for selective connection of amplifier inputs/outputs to loudspeakers, for loudspeaker detection, or for adaptation of settings to personal preferences or hearing impairments combinations of amplifiers H03F3/68; stereophonic systems H04S

Abstract

A system and method for suppressing noise in one or more of at least first and second channels include obtaining a magnitude difference of signals in the first and second channels, obtaining a magnitude sum of signals in the first and second channels, obtaining a ratio of the magnitude difference to the magnitude sum, generating an attenuation value based on the ratio, selecting an attenuator based on the magnitude difference, and attenuating a signal in a channel by the attenuation value using the selected attenuator.

Claims

1. A wind noise suppression device for suppressing wind noise in one or more of at least first and second channels, the device comprising:

a differencing module configured to obtain a magnitude difference of signals in the first and second channels;

a summing module configured to obtain a magnitude sum of signals in the first and second channels;

a ratioing module configured to obtain a ratio of the magnitude difference to the magnitude sum;

a first attenuator associated with the first channel and a second attenuator associated with the second channel;

an attenuation generator configured to generate an attenuation value based on the ratio from the ratioing module; and

an attenuation steering module configured to select the first or second attenuator based on the magnitude difference, the selected attenuator operative to attenuate the signal in the associated channel by the attenuation value.

2. The device of claim 1, wherein one or more of the differencing module, summing module, ratioing module, attenuation generator, first attenuator, and second attenuator operates in the frequency domain.

3. The device of claim 1, wherein one or more of the differencing module, summing module, ratioing module, attenuation generator, first attenuator, and second attenuator operates in the time domain.

4. The device of claim 1, wherein one or both the summing and differencing modules raises one or more associated magnitudes to an exponential power.

5. The device of claim 4, wherein the exponential power to which the summing module raises an associated magnitude is different from the exponential power to which the differencing module raises an associated magnitude.

6. The device of claim 4, wherein the exponential power is two.

7. The device of claim 1, wherein the first and second attenuators are multipliers configured to selectively multiply the signals in the associated channels by factors that are functions of the attenuation value.

8. The device of claim 1, wherein device operation is in accordance with the equation wherein ATW, represents wind noise attenuation at a particular time increment, L, is a signal in the first channel at the time increment, R, is a signal in the second channel at the time increment, p1 and p2 are numbers selected between 1 and 10, preferably 2, and k is a small constant

9. The device of claim 1, said device comprising a headset having first and second microphones respectively corresponding to the first and second channels.

10. The device of claim 1, said device being operative in discrete time and/or frequency increments.

11. The device of claim 10, wherein for each time and/or frequency increment, at least one channel remains unattenuated.

12. A method for suppressing noise in one or more of at least first and second channels, the method comprising:

obtaining a magnitude difference of signals in the first and second channels;

obtaining a magnitude sum of signals in the first and second channels;

obtaining a ratio of the magnitude difference to the magnitude sum;

generating an attenuation value based on the ratio;

selecting an attenuator from a first and a second attenuator based on the magnitude difference; and

attenuating a signal in a channel by the attenuation value using the selected first or second attenuator.

13. The method of claim 12, wherein one or more of the obtaining a magnitude difference, obtaining a magnitude sum, obtaining a ratio, generating an attenuation value, selecting an attenuator, and attenuating is conducted in the frequency domain.

14. The method of claim 12, wherein one or more of the obtaining a magnitude difference, obtaining a magnitude sum, obtaining a ratio, generating an attenuation value, selecting an attenuator, and attenuating is conducted in the time domain.

15. The method of claim 12, wherein one or both of obtaining a magnitude difference and obtaining a magnitude sum comprises raising one or more associated magnitudes to an exponential power.

16. The method of claim 15, wherein the exponential power associated with obtaining a magnitude difference is different from the exponential power associated with obtaining a magnitude sum.

17. The method of claim 15, wherein the exponential power is two.

18. The method of claim 12, wherein attenuating comprises multiplying by a factor that is a function of the attenuation value.

19. The method of claim 12, said method being conducted in accordance with the equation wherein ATW, represents wind noise attenuation at a particular time increment, L, is a signal in the first channel at the time increment, R, is a signal in the second channel at the time increment, p₁ and p₂ are numbers selected between 1 and 10, preferably 2, and k is a small constant

20. The method of claim 12, wherein said method is performed in discrete time and/or frequency increments.

21. The method of claim 20, wherein for each time and/or frequency increment, at least one channel remains unattenuated.

30. The device of claim 18, wherein said method for suppressing noise is performed in discrete time and/or frequency increments.

31. The device of claim 30, wherein for each time and/or frequency increment, at least one channel remains unattenuated.

22. A nonvolatile program storage device readable by a machine, embodying a program of instructions executable by the machine to perform a method for suppressing noise in one or more of at least first and second channels, the method comprising:

obtaining a magnitude difference of signals in the first and second channels;

obtaining a magnitude sum of signals in the first and second channels;

obtaining a ratio of the magnitude difference to the magnitude sum;

generating an attenuation value based on the ratio;

selecting an attenuator from a first and a second attenuator based on the magnitude difference; and

attenuating a signal in a channel by the attenuation value using the selected first or second attenuator.

23. The device of claim 22, wherein one or more of the obtaining a magnitude difference, obtaining a magnitude sum, obtaining a ratio, generating an attenuation value, selecting an attenuator, and attenuating is conducted in the frequency domain.

24. The device of claim 22, wherein one or more of the obtaining a magnitude difference, obtaining a magnitude sum, obtaining a ratio, generating an attenuation value, selecting an attenuator, and attenuating is conducted in the time domain.

25. The device of claim 22, wherein one or both of obtaining a magnitude difference and obtaining a magnitude sum comprises raising one or more associated magnitudes to an exponential power.

26. The device of claim 25, wherein the exponential power associated with obtaining a magnitude difference is different from the exponential power associated with obtaining a magnitude sum.

27. The device of claim 25, wherein the exponential power is two.

28. The device of claim 22, wherein attenuating comprises multiplying by a factor that is a function of the attenuation value.

29. The device of claim 22, said method being conducted in accordance with the equation wherein ATW, represents wind noise attenuation at a particular time increment, L, is a signal in the first channel at the time increment, R, is a signal in the second channel at the time increment, p1 and p2 are numbers selected between 1 and 10, preferably 2, and k is a small constant.