Beamforming microphone system

• US 7,995,771 B1
• Filed: 09/25/2006
• Issued: 08/09/2011
• Est. Priority Date: 09/25/2006
• Status: Active Grant

• Current Assignee: Advanced Bionics AG (Sonova Holding AG)
• Original Assignee: Advanced Bionics LLC (Sonova Holding AG)
• Inventors: Crawford, Scott A., Kulkarni, Abhijit, Faltys, Michael A.
• Primary Examiner(s): Goins; Davetta
• Assistant Examiner(s): DABNEY, PHYLESHA LARVINIA
• Application Number:
  US11/534,933
• Time in Patent Office: 1,779 Days
• Field of Search: 381/92, 381/312, 381/313, 381/328, 607/57, 623/10
• US Class Current: 381/92
• CPC Class Codes: H04R 25/407 Circuits for combining signals of a plurality of transducers
• CPC Class Codes: H04R 25/606 acting directly on the eardrum, the ossicles or the skull, e.g. mastoid, tooth, maxillary or mandibular bone, or mechanically stimulating the cochlea, e.g. at the oval window

Abstract

A system and method for generating a beamforming signal is disclosed. A beam forming signal is generated by disposing a first microphone and a second microphone in horizontal coplanar alignment. The first and second microphones are used to detect a known signal to generate a first response and a second response. The first response is processed along a first signal path communicatively linked to the first microphone, and the second response is processed along a second signal path communicatively linked to the second microphone. The first and second responses are matched, and the matched responses are combined to generate the beamforming signal on a combined signal path.

Claims

1. A method of generating a beamforming signal, the method comprising:

providing a plurality of microphones, including at least a first microphone and a second microphone, in horizontal coplanar alignment;

detecting a known signal through the first and second microphones to generate a first response and a second response;

processing the first response along a first signal path communicatively linked to the first microphone and the second response along a second signal path communicatively linked to the second microphone;

matching the first response with the second response; and

combining the matched first and second responses to generate a beamforming signal on a combined signal path.

2. The method of claim 1, wherein matching the first and second responses comprises:

sampling the first response and the second response at one or more locations along the first and second signal paths;

determining a first spectrum of the sampled first response, a second spectrum of the sampled second response, and a third spectrum of the known signal;

comparing the first and second spectrums against the third spectrum; and

disposing a first filter on the first signal path and a second filter on the second signal path, the first and second filters generated based on the comparisons.

3. The method of claim 1, further comprising generating a third filter disposed on the combined signal path, the third filter configured to eliminate an undesired spectral transformation of the beamforming signal.

4. The method of claim 1, wherein providing the plurality of microphones including the first and second microphones comprises

disposing a behind-the-ear microphone and an in-the-ear microphone in horizontal coplanar alignment, wherein the in-the-ear microphone is disposed in a concha of a cochlear implant user in horizontal coplanar alignment with the user'"'"'s pinnae to optimize directivity at a higher frequency band.

5. The method of claim 1, wherein providing the plurality of microphones including the first and second microphones comprises

disposing two in-the-ear microphones in horizontal coplanar alignment, wherein the two in-the-ear microphones are disposed in a concha of a cochlear implant user in horizontal coplanar alignment with the user'"'"'s pinnae to optimize directivity at a high frequency band.

6. The method of claim 1, wherein providing the plurality of microphones including the first and second microphones comprises

disposing an in-the-ear microphone and a sound port communicatively linked to a behind-the-ear microphone in horizontal coplanar alignment, wherein the sound port is disposed in horizontal coplanar alignment with the in-the-ear microphone, and wherein the in-the-ear microphone is disposed in a concha of a cochlear implant user in horizontal coplanar alignment with the user'"'"'s pinnae to optimize directivity at a high frequency band.

7. The method of claim 1, wherein providing the first and second microphones further comprises modulating a spacing between the first microphone and the second microphone to optimize directivity at a low frequency band.

8. The method of claim 6, further comprising disposing a second sound port communicatively linked to the behind-the-ear microphone, the second sound port configured to eliminate a resonance generated by the first sound port.

9. The method of claim 8, wherein disposing the first and second sound ports further comprises disposing a first sound port and a second sound port having equal length and diameter.

10. The method of claim 6, further comprising providing a resonance filter configured to eliminate a resonance generated by the first sound port.

11. The method of claim 10, wherein providing the resonance filter comprises providing a filter that generates a filter response having valleys at frequencies corresponding to locations of peaks of the resonance.

12. The method of claim 1, further comprising providing at least one additional microphone disposed in horizontal coplanar alignment with the first and second microphones.

13. A system for generating a beamforming signal, the system comprising:

a plurality of microphones, including at least a first microphone and a second microphone disposed in horizontal coplanar alignment, the first and second microphones configured to detect a known signal and generate a first response and a second response;

a processing system communicatively linked to the first and second microphones, the processing system configured to process the first response along a first signal path communicatively linked to the first microphone and the second response along a second signal path communicatively linked to the second microphone;

a first filter and a second filter disposed on the first and second signal paths, the first and second filters configured to match the first response with the second response; and

a beamforming unit operative to combine the matched first and second responses to generate a beamforming signal on a combined signal path.

14. The system of claim 13, further comprising a fitting system communicatively linked to the first and second signal paths, the fitting system configured to:

sample the first response and the second response at one or more locations along the first and second signal paths;

determine a first spectrum of the sampled first response, a second spectrum of the sampled second response, and a third spectrum of the known signal;

compare the first and second spectrums against the third spectrum; and

dispose a first filter on the first signal path and a second filter on the second signal path, the first and second filters generated based on the comparisons to match the first and second responses.

15. The system of claim 13, further comprising a third filter disposed on the combined signal path, the third filter configured to eliminate an undesired spectral transformation of the beamforming signal.

16. The system of claim 13, wherein the first and second microphones disposed in horizontal coplanar alignment comprises:

a behind-the-ear microphone; and

an in-the-ear microphone, wherein the in-the-ear microphone is disposed in a concha of a cochlear implant user in horizontal coplanar alignment with the user'"'"'s pinnae to optimize directivity at a high frequency band.

17. The system of claim 13, wherein the first and second microphones disposed in horizontal coplanar alignment comprises two in-the-ear microphones, wherein the two in-the-ear microphones are disposed in a concha of a cochlear implant user in horizontal coplanar alignment with the user'"'"'s pinnae to optimize directivity at a high frequency band.

18. The system of claim 13, wherein the first and second microphones disposed in horizontal coplanar alignment comprises an in-the-ear microphone and a sound port communicatively linked to a behind-the-ear microphone, wherein the sound port is disposed in horizontal coplanar alignment with the in-the-ear microphone, and wherein the in-the-ear microphone is disposed in a concha of a cochlear implant user in horizontal coplanar alignment with the user'"'"'s pinnae to optimize directivity at a high frequency band.

19. The system of claim 13, wherein disposing the first and second microphones further comprises modulating a spacing between the first microphone and the second microphone to optimize directivity at a low frequency band.

20. The system of claim 18, wherein the behind-the-ear microphone comprises a second sound port configured to eliminate a resonance generated by the first sound port.

21. The system of claim 20, wherein the first sound port and the second sound port have equal length and diameter.

22. The system of claim 18, further comprising a resonance filter configured to eliminate a resonance generated by the first sound port.

23. The method of claim 22, wherein the resonance filter comprises a filter that generates a response having valleys at frequencies corresponding to locations of peaks of the resonance.

24. The method of claim 13, further comprising at least one additional microphone disposed in horizontal coplanar alignment with the first and second microphones.