Voice sensing using multiple microphones

1. A noise cancelling headset ( 100 ) comprising:

first and second earpieces ( 102 ), each earpiece comprising a respective feedback microphone ( 104 ), a respective feed-forward microphone ( 110 ), and a respective output driver ( 112 );

a noise cancellation system comprising, for each earpiece,

a noise cancellation feedback filter ( 302 ) receiving an input from at least the first feedback microphone and producing a noise cancellation filtered feedback signal,

a noise cancellation feed-forward filter ( 304 ) receiving an input from at least the first feed-forward microphone and producing a noise cancellation filtered feed-forward signal,

a noise cancellation summer ( 310 , 320 ) combining the noise cancellation filtered feedback signal and the noise cancellation filtered feed-forward signal and producing a noise cancellation output signal,

a first feedback voice filter ( 302 ) receiving an input from at least the first feedback microphone and producing a first voice-filtered feedback signal;

a first feed-forward voice filter ( 304 ) receiving an input from at least the first feed-forward microphone and producing a first voice-filtered feed-forward signal;

a voice summer ( 310 , 320 ) combining the first voice-filtered feedback signal and the first voice-filtered feed-forward signal and producing a voice output signal representing the voice of a user of the headset; and

a communications interface providing the voice output signal as a voice output from the headset.

2. The headset of claim 1 further comprising a second feedback voice filter ( 308 ) receiving an input from the second feedback microphone and producing a second voice-filtered feedback signal,

wherein the voice summer combines the first voice filtered feedback signal with the second voice filtered feedback signal.

3. The headset of claim 1 further comprising a second feed-forward voice filter ( 306 ) receiving an input from the second feed-forward microphone and producing a second voice-filtered feed-forward signal,

wherein the voice summer combines the first voice-filtered feed-forward signal with the second voice-filtered feed-forward signal.

4. The headset of claim 1 further comprising a pre-filter summer ( 312 ) combining the first and second feedback microphone inputs and providing a summed feedback microphone signal to the first feedback voice filter ( 316 ).

5. The headset of claim 1 further comprising a pre-filter summer ( 314 ) combining the first and second feed-forward microphone inputs and providing a summed feed-forward microphone signal to the first feed-forward voice filter ( 318 ).

6. The headset of claim 1 further comprising:

a second feedback voice filter ( 308 ) receiving an input from the second feedback microphone and producing a second voice-filtered feedback signal;

a second feed-forward voice filter ( 306 ) receiving an input from the second feed-forward microphone and producing a second voice-filtered feed-forward signal; and

a second voice summer ( 322 ) combining the second voice-filtered feedback signal with the second voice-filtered feed-forward signal to produce a second voice output signal.

7. The headset of claim 1 wherein:

at least the first earpiece further comprises an additional external microphone ( 324 R, 324 L), and

the first feed-forward voice filter comprises a feed-forward array processing filter ( 326 R, 326 L) receiving inputs from the first or second feed-forward microphone and the additional external microphone, and producing an array-filtered signal,

wherein the first summer combines the array filtered signal with at least the first voice-filtered feedback signal to produce the output signal.

8. The headset of claim 1 further comprising:

a joint housing connected to cords leading from the earpieces, the joint housing including an array of microphones ( 330 , 332 ); and

an array processing filter ( 336 ) receiving inputs from the array of microphones and the first and second feed-forward microphones and producing an array-filtered signal;

wherein the first voice summer ( 326 ) combines the array filtered signal with at least the first voice-filtered feedback signal to produce the output signal.

9. The headset of claim 1 further comprising

a first comparison summer ( 350 ) combining the first and second feedback microphone inputs and providing a summed feedback microphone signal to a comparator ( 354 );

a second comparison summer ( 352 ) combining the first and second feed-forward microphone inputs and providing a summed feed-forward microphone signal to the comparator;

an output of the comparator controlling operation of the first feedback voice filter ( 356 ) and the first feed-forward voice filter ( 358 ) based on a comparison of the summed feedback microphone signal with the summed feed-forward microphone signal.

10. The headset of claim 9 wherein the output of the comparator deactivates the first feedback voice filter when the comparison indicates that the summed feedback microphone signals have less signal content than the summed feed-forward microphone signals above 500 Hz.

11. The headset of claim 9 wherein the output of the comparator deactivates the first feed-forward voice filter when the comparison indicates that the summed feedback microphone signals have more signal content than the summed feed-forward microphone signals between 150 Hz and 500 Hz.

12. A method of generating a voice communication signal in an in-ear noise cancelling headset comprising two earpieces, each earpiece comprising a respective feedback microphone, a respective feed-forward microphone, and a respective output driver, the method comprising:

filtering an input from at least the first feedback microphone to produce a first noise cancellation filtered feedback signal;

filtering an input from at least the first feed-forward microphone to produce a first noise cancellation filtered feed-forward signal;

combining at least the first filtered feedback signal and the first filtered feed-forward signal to produce a first noise cancellation output signal;

filtering the input from at least the first feedback microphone to produce a first voice-filtered feedback signal;

filtering the input from at least the first feed-forward microphone to produce a first voice-filtered feed-forward signal;

combining at least the first voice-filtered feedback signal and the first voice-filtered feed-forward signal to produce a first voice output signal representing the voice of a user of the headset; and

outputting the first voice output signal as the voice communication signal.

13. The method of claim 12 , further comprising:

filtering an input from the second feedback microphone to produce a second voice-filtered feedback signal, and

combining the first filtered feedback signal with the second voice-filtered feedback signal.

14. The method of claim 12 , further comprising:

filtering the input from the first feed-forward microphone in combination with a signal from an additional external microphone to produce an array-filtered signal,

wherein the combining comprises combining the array-filtered signal with the first voice-filtered feedback signal.

15. The method of claim 12 , further comprising:

combining the inputs from the first and second feedback microphones, to produce a summed feedback microphone signal,

combining the inputs from the first and second feed-forward microphones, to produce a summed feed-forward microphone signal,

comparing the summed feedback microphone signal to the summed feed-forward microphone signal, and

based on the result of the comparison, controlling operation of the filtering of the feedback microphone input and the filtering of the feed-forward microphone input.