Method and apparatus for microphone matching for wearable directional hearing device using wearer's own voice

1. An apparatus for processing sounds, including sounds from a user's mouth, comprising:

a first microphone to produce a first output signal;

a second microphone to produce a second output signal;

a first directional filter adapted to receive the first output signal and produce a first directional output signal;

a digital signal processor adapted to receive signals representative of the sounds from the user's mouth from at least one or more of the first and second microphones and to detect at least an average fundamental frequency of voice, or pitch output;

a voice detection circuit adapted to receive the second output signal and the pitch output and to produce a voice detection trigger;

a mismatch filter adapted to receive and process the second output signal, the voice detection trigger, and an error signal, wherein the error signal is a difference between the first output signal and an output of the mismatch filter;

a second directional filter adapted to receive the mismatch output and produce a second directional output signal; and

a first summing circuit adapted to receive the first directional output signal and the second directional output signal and to provide a summed directional output signal,

wherein in use, at least the first microphone and the second microphone are in relatively constant spatial position with respect to the user's mouth.

2. The apparatus of claim 1 , wherein the error signal is produced by a second summing circuit adapted to subtract the output of the mismatch filter from the first output signal.

3. The apparatus of claim 1 , wherein the mismatch filter is an adaptive filter.

4. The apparatus of claim 3 , wherein the adaptive filter is an LMS adaptive filter.

5. The apparatus of claim 4 , wherein the LMS adaptive filter comprises:

a least mean squares processor (LMS processor) configured to receive the second output signal and the voice detection trigger and the error signal, and to provide a plurality of LMS coefficients; and

a finite impulse response filter (FIR filter) configured to receive the plurality of LMS coefficients and the second output signal and adapted to produce the matched output.

6. The apparatus of claim 5 , wherein the first microphone and second microphone are mounted in a behind-the-ear hearing aid housing.

7. The apparatus of claim 5 , wherein the first microphone and second microphone are mounted in an in-the-ear hearing aid housing.

8. The apparatus of claim 5 , wherein the first microphone and second microphone are mounted in an in-the-canal hearing aid housing.

9. The apparatus of claim 5 , wherein the first microphone and second microphone are mounted in a completely-in-the-canal hearing aid housing.

10. The apparatus of claim 5 , wherein the apparatus is at least partially realized using a digital signal processor.

11. A method for matching at least a first microphone to a second microphone, using a user's voice from the user's mouth, comprising:

processing the user's voice as received by at least one microphone to determine a frequency profile associated with voice of the user;

detecting intervals where the user is speaking using the frequency profile; and

adaptively canceling variations in microphone reception between the first microphone and the second microphone during the intervals and when the first microphone and second microphone are in relatively constant spatial position with respect to the user's mouth.

12. The method of claim 11 , wherein the processing is performed using voice received by the first microphone.

13. The method of claim 11 , wherein the processing is performed using voice received by the second microphone.

14. The method of claim 11 , wherein the processing is performed using voice received by the first and second microphone.

15. The method of claim 11 , wherein the adaptively canceling variations includes an LMS filter adaptation process.

16. The method of claim 11 , comprising performing the adaptively canceling variations in a behind-the-ear hearing aid.

17. The method of claim 11 , comprising performing the adaptively canceling variations in an in-the-ear hearing aid.

18. The method of claim 11 , comprising performing the adaptively canceling variations in an in-the-canal hearing aid.

19. The method of claim 11 , comprising performing the adaptively canceling variations in a completely-in-the-canal hearing aid.

20. The method of claim 11 , comprising performing the adaptively canceling variations using a digital signal processor realization.