Methods, apparatuses and computer program products for facilitating directional audio capture with multiple microphones

• US 10,560,783 B2
• Filed: 03/22/2018
• Issued: 02/11/2020
• Est. Priority Date: 10/15/2012
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Technologies Oy (Nokia Corporation)
• Inventors: Huttunen, Anu Hannele, Makinen, Jorma Juhani
• Primary Examiner(s): Gauthier, Gerald
• Application Number:
  US15/928,257
• Publication Number:
  US 20180213326A1
• Time in Patent Office: 691 Days
• Field of Search: 342378, 37940602, 381 7111, 381 92, 381 943, 381313, 381 26, 381 86, 381307, 702190, 704233, 367125
• CPC Class Codes: H04R 1/265 of microphones
• CPC Class Codes: H04R 1/326 for microphones H04R1/34 and H04R1/40 take precedence
• CPC Class Codes: H04R 2201/405 Non-uniform arrays of transducers or a plurality of uniform arrays with different transducer spacing
• CPC Class Codes: H04R 2203/12 Beamforming aspects for stereophonic sound reproduction with loudspeaker arrays
• CPC Class Codes: H04R 2430/03 Synergistic effects of band splitting and sub-band processing
• 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 5/027 Spatial or constructional arrangements of microphones, e.g. in dummy heads

Abstract

An apparatus for providing directional audio capture may include a processor and memory storing executable computer program code that cause the apparatus to at least perform operations including assigning at least one beam direction, among a plurality of beam directions, in which to direct directionality of an output signal of one or more microphones. The computer program code may further cause the apparatus to divide microphone signals of the microphones into selected frequency subbands wherein an analysis performed. The computer program code may further cause the apparatus to select at least one set of microphones of the apparatus for selected frequency subbands. The computer program code may further cause the apparatus to optimize the assigned at least one beam direction by adjusting a beamformer parameter(s) based on the selected set of microphones and at least one of the selected frequency subbands. Corresponding methods and computer program products are also provided.

Claims

1. An apparatus comprising:

a directional audio capture module; and

a plurality of microphones positioned at predetermined locations of the apparatus;

wherein the directional audio capture module is configured to;

assign at least one direction, among a plurality of directions, in which to direct directionality of an output signal of one or more of the plurality of microphones based on a respective selected application, among a plurality of applications;

select at least one of a first set of microphones comprising at least two microphones for a first frequency band and a second set of microphones comprising at least two other microphones for a second frequency band based in part on the selected application; and

adjust the output signal for the assigned at least one direction by adjusting at least one parameter of the assigned at least one direction based on output signals of the selected first and second sets of microphones, wherein respective sets of microphone signals for the first and second frequency bands are processed by the adjusted at least one parameter.

2. The apparatus of claim 1, wherein:

the plurality of applications comprise stereo recording, directional mono recording, surround sound recording, directional stereo recording, telephony processing or speech recognition processing.

3. The apparatus of claim 1, further comprising at least one processor wherein:

the at least one processor or the directional audio capture module is further configured to;

adjust each direction, of the plurality of directions, and each frequency band, among a plurality of frequency bands, independently, for respective applications of the plurality of applications.

4. The apparatus of claim 3, wherein each of the plurality of directions are predefined to correspond to the respective applications.

5. The apparatus of claim 1, wherein the directional audio capture module is further configured to:

select the first set of microphones and the second set of microphones based in part on a distance between the microphones of the first set and the microphones of the second set.

6. The apparatus of claim 1, wherein the directional audio capture module is further configured to:

detect that at least one of the first frequency band or the second frequency band comprises a low frequency band in response to detecting that a respective frequency is below a frequency threshold.

7. The apparatus of claim 1, wherein the directional audio capture module is further configured to:

detect that at least one of the first frequency band or the second frequency band comprises a high frequency band in response to detecting that a respective frequency is greater than or equal to a frequency threshold.

8. The apparatus of claim 1, wherein one of the first frequency band or the second frequency band comprises a low frequency band and the other of the first frequency band or the second frequency band comprises a high frequency band, and wherein the directional audio capture module is further configured to:

utilize the microphones of the first set in the low frequency band and the microphones of the second set in the high frequency band to support a hands-free telephony application or another audio processing application, among the plurality of applications.

9. The apparatus of claim 1, wherein the directional audio capture module is further configured to:

select an alternative set of microphones, of the plurality of microphones, to replace at least one of the first set of microphones or the second set of microphones in response to detecting an indication of a selection of another application, among the plurality of applications.

10. The apparatus of claim 1, wherein:

the at least one parameter of the assigned at least one direction comprises one or more filter coefficients.

11. A method comprising:

assigning, via a directional audio capture module of an apparatus, at least one direction, among a plurality of directions, in which to direct directionality of an output signal of one or more of a plurality of microphones based on a respective selected application, among a plurality of applications;

selecting, via the directional audio capture module, at least one of a first set of microphones comprising at least two microphones for a first frequency band and a second set of microphones comprising at least two other microphones for a second frequency band based in part on the selected application; and

adjusting, via the directional audio capture module, the output signal for the assigned at least one direction by adjusting at least one parameter of the assigned at least one direction based on the selected first and second sets of microphones, wherein respective sets of microphone signals for the first and second frequency bands are processed by the adjusted at least one parameter.

12. The method of claim 11, wherein:

the plurality of applications comprise stereo recording, directional mono recording, surround sound recording, directional stereo recording, telephony processing or speech recognition processing.

13. The method of claim 11, further comprising:

adjusting, via a processor of the apparatus or the directional audio capture module, each direction, of the plurality of directions, and each frequency band, among a plurality of frequency bands, independently, for respective applications of the plurality of applications.

14. The method of claim 13, wherein each of the plurality of directions are predefined to correspond to the respective applications.

15. The method of claim 11, further comprising:

selecting, via the directional audio capture module, the first set of microphones and the second set of microphones based in part on a distance between the microphones of the first set and the microphones of the second set.

16. The method of claim 11, further comprising:

detecting, via the directional audio capture module, that at least one of the first frequency band or the second frequency band comprises a low frequency band in response to detecting that a respective frequency is below a frequency threshold.

17. The method of claim 11, further comprising:

detecting, via the directional audio capture module, that at least one of the first frequency band or the second frequency band comprises a high frequency band in response to detecting that a respective frequency is greater than or equal to a frequency threshold.

18. The method of claim 11, wherein one of the first frequency band or the second frequency band comprises a low frequency band and the other of the first frequency band or the second frequency band comprises a high frequency band, the method further comprising:

utilizing the microphones of the first set in the low frequency band and the microphones of the second set in the high frequency band to support a hands-free telephony application or another audio processing application, among the plurality of applications.

19. The method of claim 11, further comprising:

selecting, via the directional audio capture module, an alternative set of microphones, of the plurality of microphones, to replace at least one of the first set of microphones or the second set of microphones in response to detecting an indication of a selection of another application, among the plurality of applications.

20. The method of claim 11, wherein:

the at least one parameter of the assigned at least one direction comprises one or more filter coefficients.