Wind Suppression/Replacement Component for use with Electronic Systems

• US 20100278352A1
• Filed: 05/03/2010
• Published: 11/04/2010
• Est. Priority Date: 05/25/2007
• Status: Active Grant

• Current Assignee: Jawbone Innovations, LLC
• Original Assignee: AliphCom, Inc. (AliphCom Corp.)
• Inventors: Goertz, Michael, Burnett, Gregory, Petit, Nicolas
• Granted Patent: US 8,488,803 B2
• Time in Patent Office: Days
• US Class Current: 381/71.1
• CPC Class Codes: G10L 2021/02165 Two microphones, one receiving mainly the noise signal and the other one mainly the speech signal
• CPC Class Codes: G10L 21/0208 Noise filtering
• CPC Class Codes: H04R 1/1083 Reduction of ambient noise active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 2410/07 Mechanical or electrical reduction of wind noise generated by wind passing a microphone
• CPC Class Codes: H04R 3/002 Damping circuit arrangements for transducers, e.g. motional feedback circuits
• 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 3/02 for preventing acoustic reaction , i.e. acoustic oscillatory feedback specially adapted for hearing aids H04R25/453
• CPC Class Codes: H04R 3/04 for correcting frequency response

Abstract

Systems and methods to reduce the negative impact of wind on an electronic system include use of a first detector that receives a first signal and a second detector that receives a second signal. A voice activity detector (VAD) coupled to the first detector generates a VAD signal when the first signal corresponds to voiced speech. A wind detector coupled to the second detector correlates signals received at the second detector and derives from the correlation wind metrics that characterize wind noise that is acoustic disturbance corresponding to at least one of air flow and air pressure in the second detector. The wind detector controls a configuration of the second detector according to the wind metrics. The wind detector uses the wind metrics to dynamically control mixing of the first signal and the second signal to generate an output signal for transmission.

Claims

1. A method comprising:

receiving a first signal at a first detector and a second signal at a second detector;

determining a correlation between signals received at the second detector and deriving from the correlation a plurality of wind metrics that characterize wind noise that is acoustic disturbance corresponding to at least one of air flow and air pressure in the second detector;

controlling a configuration of the second detector according to the plurality of wind metrics; and

generating an output signal for transmission by dynamically mixing the first signal and the second signal according to the plurality of wind metrics.

2. The method of claim 1, wherein the first detector is a vibration sensor.

3. The method of claim 2, wherein the first detector is a skin surface microphone (SSM).

4. The method of claim 2, wherein the second detector is an acoustic sensor.

5. The method of claim 4, wherein the second detector comprises two omnidirectional microphones.

6. The system of claim 5, comprising positioning the two omnidirectional microphones adjacent one another and separating the two omnidirectional microphones by a distance approximately in a range of 10 millimeters (mm) to 40 mm.

7. The method of claim 1, wherein determining the correlation comprises calculating energy of an adaptive filter error.

8. The method of claim 7, comprising applying the energy to a first exponential averaging filter and a second exponential averaging filter.

9. The method of claim 7, comprising deriving an instantaneous wind level from the energy, wherein the instantaneous wind level represents an instant wind level of the wind noise.

10. The method of claim 9, wherein the plurality of wind metrics comprise a wind present metric that characterizes the instantaneous wind level relative to a present wind threshold over which the wind noise negatively affects electronic operations in a host electronic system.

11. The method of claim 9, wherein the plurality of wind metrics comprise a wind mode metric that characterizes the instantaneous wind level relative to a wind high threshold over which the wind noise is considered to have a relatively high impact on audio intelligibility in a host electronic system.

12. The method of claim 7, comprising deriving a current wind level from the energy, wherein the current wind level represents an average current wind level of the wind noise.

13. The method of claim 12, wherein the plurality of wind metrics comprise a wind index metric that characterizes the current wind level relative to a minimum wind threshold under which the wind noise is considered to have a negligible impact on noise suppression and audio intelligibility in a host electronic system.

14. The method of claim 1, comprising controlling a gain applied to the first signal in response to the plurality of wind metrics and a voice activity detection (VAD) signal.

15. The method of claim 14, comprising adjusting the gain when the plurality of wind metrics indicates no wind is present.

16. The method of claim 15, wherein the plurality of wind metrics is a wind present metric that characterizes an instantaneous wind level derived from the second signal relative to a present wind threshold over which the wind noise negatively affects electronic operations in a host electronic system.

17. The method of claim 14, comprising adjusting the gain when the VAD signal indicates the first signal corresponds to voiced speech.

18. The method of claim 14, comprising adjusting the gain to match a first root mean square (RMS) of the first signal to a second RMS of a noise-suppressed speech signal.

19. The method of claim 14, comprising generating a VAD signal when the first signal corresponds to voiced speech, and using the VAD signal to noise gate the first signal.

20. The method of claim 1, wherein the controlling of the configuration of the second detector according to the plurality of wind metrics comprises use of a wind mode metric that characterizes instantaneous wind level relative to a wind high threshold over which the wind noise is considered to have a relatively high impact on audio intelligibility in a host electronic system.

21. The method of claim 20, wherein the controlling of the configuration of the second detector comprises, when the wind mode metric indicates instantaneous wind level exceeds the wind high threshold, generating a summed detector signal by summing signals from each of two microphones of the second detector.

22. The method of claim 21, wherein the controlling of the configuration of the second detector comprises applying single-microphone noise suppression to the summed detector signal.

23. The method of claim 20, wherein the controlling of the configuration of the second detector comprises separately processing signals from each of two microphones of the second detector when the wind mode metric indicates instantaneous wind level is below the wind high threshold.

24. The method of claim 23, wherein the controlling of the configuration of the second detector comprises applying dual-microphone noise suppression to the signals from the two microphones.

25. The method of claim 1, wherein dynamically mixing the first signal and the second signal according to the plurality of wind metrics comprises dynamically adjusting a response of a first filter to which the first signal is applied and dynamically adjusting a response of a second filter to which the second signal is applied.

26. The method of claim 25, wherein the first filter is a low-pass filter and the second filter is a high-pass filter.

27. The method of claim 25, wherein the plurality of wind metrics is a wind index metric that characterizes a current wind level relative to a minimum wind threshold under which the wind noise is considered to have a negligible impact on noise suppression and audio intelligibility in a host electronic system, wherein the current wind level represents an average current wind level of the wind noise.

28. The method of claim 27, comprising estimating a wind frequency response of the wind noise from the wind index metric.

29. The method of claim 1, comprising generating a comfort wind component and adding the comfort wind component to receive and transmit audio, wherein the comfort wind component provides listener awareness of wind presence.

30. The method of claim 29, comprising generating the comfort wind component by subtracting signals from each of two microphones of the second detector to generate a difference signal.

31. The method of claim 30, comprising modulating the difference signal by a gain to generate a modulated signal.

32. The method of claim 31, wherein the gain comprises a static gain that provides an appropriate level of wind noise feedback in a loudspeaker.

33. The method of claim 32, wherein the gain comprises a gating factor derived from a wind present metric that characterizes an instantaneous wind level derived from the second signal relative to a present wind threshold over which the wind noise negatively affects electronic operations in a host electronic system.

34. The method of claim 31, comprising filtering the modulated signal to provide the comfort wind component, the filtering comprising limiting an amount of low-frequency wind noise and high-frequency wind noise reaching a receiver.

35. A method comprising:

receiving a first signal at a first detector and a second signal at a second detector;

determining a correlation between signals received at the second detector and deriving from the correlation a plurality of wind metrics that characterize wind noise that is acoustic disturbance corresponding to at least one of air flow and air pressure in the second detector; and

controlling a configuration of the second detector according to the plurality of wind metrics.

36. A method comprising:

receiving a first signal at a first detector and a second signal at a second detector;

determining a correlation between signals received at the second detector and deriving from the correlation a plurality of wind metrics that characterize wind noise that is acoustic disturbance corresponding to at least one of air flow and air pressure in the second detector; and

generating an output signal for transmission by dynamically mixing the first signal and the second signal according to the plurality of wind metrics.