Voice activity detection based on plural voice activity detectors

1. A method of voice activity detection (VAD), comprising:

receiving a first VAD signal from a first voice activity detector included in a device;

receiving a second VAD signal from a second voice activity detector not included in the device;

combining the first and second VAD signals into a VAD output signal; and

detecting voice activity based on the VAD output signal.

2. The method of claim 1 , further comprising:

weighting the first VAD signal based on environmental conditions.

3. The method of claim 2 , wherein the environmental conditions include a signal-to-noise ratio (SNR) measured at the device.

4. The method of claim 1 , further comprising:

weighting the second VAD signal based on environmental conditions.

5. The method of claim 4 , wherein the environmental conditions include a signal-to-noise ratio (SNR) measured at an external device including the second voice activity detector.

6. The method of claim 1 , further comprising:

determining a function of the second voice activity detector.

7. The method of claim 6 , wherein the function of the second voice activity detector is based on a bone conduction microphone, an audio microphone, a skin vibration sensor, an array of microphone, or a radar signal.

8. The method of claim 1 , further comprising:

transmitting the second VAD signal over a wireless link.

9. The method of claim 8 , wherein the wireless link is a Bluetooth wireless link.

10. A method of voice activity detection (VAD), comprising:

providing a first device and a second device, each device configured to communicate with one another by way of a wireless link;

determining a VAD signal in the second device;

at the second device, setting a flag based on the VAD signal, the flag being included in a packet containing digitized audio, wherein the flag is a one-bit value included in a Bluetooth packet header;

transmitting the packet from second device to the first device by way of the wireless link; and

detecting voice activity at the first device based on the flag included in the packet.

11. A system, comprising:

a first voice activity detector included in a device, configured to produce a first voice activity detection (VAD) signal;

a second voice activity detector not included in the device, configured to produce a second voice activity detection (VAD) signal; and

control logic, in communication with the first and second voice activity detectors, configured to combine the first and second VAD signals into a VAD output signal.

12. The system of claim 11 , further comprising:

a processor receiving the VAD output signal.

13. The system of claim 12 , wherein the processor includes a vocoder.

14. The system of claim 11 , wherein the device is a wireless handset.

15. The system of claim 11 , wherein the second voice activity detector is included in a headset in communication with the device.

16. The system of claim 15 , wherein the headset is a wireless headset.

17. The system of claim 11 , wherein the second VAD signal is transmitted to the control logic as a single bit value included in a Bluetooth header.

18. The system of claim 12 , wherein the control logic is included in the device.

19. A system, comprising:

first means for detecting voice activity at a first location;

second means for detecting voice activity at a second location; and

means for combining output from the first and second means into a voice activity detection (VAD) output signal.

20. The system of claim 19 , further comprising:

processor means for receiving the VAD output signal.

21. The system of claim 19 , wherein the first means is included in a wireless handset.

22. The system of claim 19 , wherein the second means is included in a headset in communication with a device.

23. The system of claim 22 , wherein the headset is a wireless headset.

24. The system of claim 19 , further comprising means for transmitting a VAD signal from the first or second means to the means for combining as a single bit value included in a Bluetooth header.

25. The system of claim 19 , wherein the means for combining is included at the first location.

26. A non-transitory computer-readable medium embodying a set of instructions executable by one or more processors, comprising:

code for receiving a first VAD signal from a first voice activity detector included in a device;

code for receiving a second VAD signal from a second voice activity detector not included in the device; and

code for combining the first and second VAD signals into a VAD output signal.

27. The computer-readable medium of claim 26 , further comprising:

code for detecting voice activity based on the VAD output signal.

28. The computer-readable medium of claim 26 , further comprising:

code for weighting the first VAD signal based on environmental conditions.

29. The computer-readable medium of claim 28 , wherein the environmental conditions include a signal-to-noise ratio (SNR) measured at the device.

30. The computer-readable medium of claim 26 , further comprising:

code for weighting the second VAD signal based on environmental conditions.

31. The computer-readable medium of claim 30 , wherein the environmental conditions include a signal-to-noise ratio (SNR) measured at an external device including the second voice activity detector.