Systems, methods, apparatus, and computer-readable media for head tracking based on recorded sound signals

• US 8,855,341 B2
• Filed: 10/24/2011
• Issued: 10/07/2014
• Est. Priority Date: 10/25/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Kim, Lae-Hoon, Xiang, Pei, Visser, Erik
• Primary Examiner(s): Chin, Vivian
• Assistant Examiner(s): SUTHERS, DOUGLAS JOHN
• Application Number:
  US13/280,203
• Publication Number:
  US 20120128166A1
• Time in Patent Office: 1,079 Days
• Field of Search: 381/309, 381/310, 381/58, 381/56, 381/92, 381/122
• US Class Current: 381/310
• CPC Class Codes: H04R 1/1041 Mechanical or electronic switches, or control elements switches in general H01H
• CPC Class Codes: H04R 1/1066 Constructional aspects of the interconnection between earpiece and earpiece support earpiece support for monophonic headphones H04R1/105; earpiece support for stereophonic headphones H04R5/0335
• CPC Class Codes: H04R 1/1075 Mountings of transducers in earphones or headphones
• CPC Class Codes: H04R 1/1083 Reduction of ambient noise active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06
• CPC Class Codes: H04R 2201/107 Monophonic and stereophonic headphones with microphone for two-way hands free communication
• CPC Class Codes: H04R 2201/403 Linear arrays of transducers
• CPC Class Codes: H04R 2420/01 Input selection or mixing for amplifiers or loudspeakers for hearing aids H04R25/43
• CPC Class Codes: H04R 2420/05 Detection of connection of loudspeakers or headphones to amplifiers
• CPC Class Codes: H04R 2430/21 Direction finding using differential microphone array [DMA]
• CPC Class Codes: H04R 2499/11 Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's
• 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 3/12 for distributing signals to two or more loudspeakers specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04R 5/033 Headphones for stereophonic communication details thereof, e.g. relating to batteries, cables or control elements H04R1/10
• CPC Class Codes: H04S 2400/15 Aspects of sound capture and related signal processing for recording or reproduction
• CPC Class Codes: H04S 2420/03 Application of parametric coding in stereophonic audio systems
• CPC Class Codes: H04S 7/303 Tracking of listener position or orientation
• CPC Class Codes: H04S 7/304 For headphones

Abstract

Systems, methods, apparatus, and machine-readable media for detecting head movement based on recorded sound signals are described.

Claims

1. A method of audio signal processing, said method comprising:

calculating a first cross-correlation between a left microphone signal and a reference microphone signal;

calculating a second cross-correlation between a right microphone signal and the reference microphone signal; and

based on information from the first and second calculated cross-correlations, determining a corresponding orientation of a head of a user,

wherein the left microphone signal is based on a signal produced by a left microphone located at a left side of the head, the right microphone signal is based on a signal produced by a right microphone located at a right side of the head opposite to the left side, and the reference microphone signal is based on a signal produced by a reference microphone, and

wherein said reference microphone is located such that (A) as the head rotates in a first direction, a left distance between the left microphone and the reference microphone decreases and a right distance between the right microphone and the reference microphone increases and (B) as the head rotates in a second direction opposite to the first direction, the left distance increases and the right distance decreases.

2. The method according to claim 1, wherein a line that passes through a center of the left microphone and a center of the right microphone rotates with the head.

3. The method according to claim 1, wherein the left microphone is worn on the head to move with a left ear of the user, and wherein the right microphone is worn on the head to move with a right ear of the user.

4. The method according to claim 1, wherein the left microphone is located not more than five centimeters from an opening of a left ear canal of the user, and wherein the right microphone is located not more than five centimeters from an opening of a right ear canal of the user.

5. The method according to claim 1, wherein said reference microphone is located at a front side of a midcoronal plane of a body of the user.

6. The method according to claim 1, wherein said reference microphone is located closer to a midsagittal plane of a body of the user than to a midcoronal plane of the body of the user.

7. The method according to claim 1, wherein a location of the reference microphone is invariant to rotation of the head.

8. The method according to claim 1, wherein at least half of the energy of each of the left, right, and reference microphone signals is at frequencies not greater than fifteen hundred Hertz.

9. The method according to claim 1, wherein said method includes calculating a rotation of the head, based on said determined orientation.

10. The method according to claim 1, wherein said method includes:

selecting an acoustic transfer function, based on said determined orientation; and

driving a pair of loudspeakers based on the selected acoustic transfer function.

11. The method according to claim 10, wherein the selected acoustic transfer function includes a room impulse response.

12. The method according to claim 10, wherein the selected acoustic transfer function includes a head-related transfer function.

13. The method according to claim 10, wherein said driving includes performing a crosstalk cancellation operation that is based on the selected acoustic transfer function.

14. The method according to claim 1, wherein said method comprises:

updating an adaptive filtering operation, based on information from the signal produced by the left microphone and information from the signal produced by the right microphone; and

based on the updated adaptive filtering operation, driving a pair of loudspeakers.

15. The method according to claim 14, wherein the signal produced by the left microphone and the signal produced by the right microphone are produced in response to a sound field produced by the pair of loudspeakers.

16. The method according to claim 10, wherein the pair of loudspeakers includes a left loudspeaker worn on the head to move with a left ear of the user, and a right loudspeaker worn on the head to move with a right ear of the user.

17. An apparatus for audio signal processing, said apparatus comprising:

means for calculating a first cross-correlation between a left microphone signal and a reference microphone signal;

means for calculating a second cross-correlation between a right microphone signal and the reference microphone signal; and

means for determining a corresponding orientation of a head of a user, based on information from the first and second calculated cross-correlations,

wherein the left microphone signal is based on a signal produced by a left microphone located at a left side of the head, the right microphone signal is based on a signal produced by a right microphone located at a right side of the head opposite to the left side, and the reference microphone signal is based on a signal produced by a reference microphone, and

wherein said reference microphone is located such that (A) as the head rotates in a first direction, a left distance between the left microphone and the reference microphone decreases and a right distance between the right microphone and the reference microphone increases and (B) as the head rotates in a second direction opposite to the first direction, the left distance increases and the right distance decreases.

18. The apparatus according to claim 17, wherein, during use of the apparatus, a line that passes through a center of the left microphone and a center of the right microphone rotates with the head.

19. The apparatus according to claim 17, wherein the left microphone is configured to be worn, during use of the apparatus, on the head to move with a left ear of the user, and wherein the right microphone is configured to be worn, during use of the apparatus, on the head to move with a right ear of the user.

20. The apparatus according to claim 17, wherein the left microphone is configured to be located, during use of the apparatus, not more than five centimeters from an opening of a left ear canal of the user, and wherein the right microphone is configured to be located, during use of the apparatus, not more than five centimeters from an opening of a right ear canal of the user.

21. The apparatus according to claim 17, wherein said reference microphone is configured to be located, during use of the apparatus, at a front side of a midcoronal plane of a body of the user.

22. The apparatus according to claim 17, wherein said reference microphone is configured to be located, during use of the apparatus, closer to a midsagittal plane of a body of the user than to a midcoronal plane of the body of the user.

23. The apparatus according to claim 17, wherein a location of the reference microphone is invariant to rotation of the head.

24. The apparatus according to claim 17, wherein at least half of the energy of each of the left, right, and reference microphone signals is at frequencies not greater than fifteen hundred Hertz.

25. The apparatus according to claim 17, wherein said apparatus includes means for calculating a rotation of the head, based on said determined orientation.

26. The apparatus according to claim 17, wherein said apparatus includes:

means for selecting one among a set of acoustic transfer functions, based on said determined orientation; and

means for driving a pair of loudspeakers based on the selected acoustic transfer function.

27. The apparatus according to claim 26, wherein the selected acoustic transfer function includes a room impulse response.

28. The apparatus according to claim 26, wherein the selected acoustic transfer function includes a head-related transfer function.

29. The apparatus according to claim 26, wherein said means for driving is configured to perform a crosstalk cancellation operation that is based on the selected acoustic transfer function.

30. The apparatus according to claim 17, wherein said apparatus comprises:

means for updating an adaptive filtering operation, based on information from the signal produced by the left microphone and information from the signal produced by the right microphone; and

means for driving a pair of loudspeakers based on the updated adaptive filtering operation.

31. The apparatus according to claim 30, wherein the signal produced by the left microphone and the signal produced by the right microphone are produced in response to a sound field produced by the pair of loudspeakers.

32. The apparatus according to claim 26, wherein the pair of loudspeakers includes a left loudspeaker worn on the head to move with a left ear of the user, and a right loudspeaker worn on the head to move with a right ear of the user.

33. An apparatus for audio signal processing, said apparatus comprising:

a left microphone configured to be located, during use of the apparatus, at a left side of a head of a user;

a right microphone configured to be located, during use of the apparatus, at a right side of the head opposite to the left side;

a reference microphone configured to be located, during use of the apparatus, such that (A) as the head rotates in a first direction, a left distance between the left microphone and the reference microphone decreases and a right distance between the right microphone and the reference microphone increases and (B) as the head rotates in a second direction opposite to the first direction, the left distance increases and the right distance decreases;

a first cross-correlator configured to calculate a first cross-correlation between a reference microphone signal that is based on a signal produced by the reference microphone and a left microphone signal that is based on a signal produced by the left microphone;

a second cross-correlator configured to calculate a second cross-correlation between the reference microphone signal and a right microphone signal that is based on a signal produced by the right microphone; and

an orientation calculator configured to determine a corresponding orientation of a head of a user, based on information from the first and second calculated cross-correlations.

34. The apparatus according to claim 33, wherein, during use of the apparatus, a line that passes through a center of the left microphone and a center of the right microphone rotates with the head.

35. The apparatus according to claim 33, wherein the left microphone is configured to be worn, during use of the apparatus, on the head to move with a left ear of the user, and wherein the right microphone is configured to be worn, during use of the apparatus, on the head to move with a right ear of the user.

36. The apparatus according to claim 33, wherein the left microphone is configured to be located, during use of the apparatus, not more than five centimeters from an opening of a left ear canal of the user, and wherein the right microphone is configured to be located, during use of the apparatus, not more than five centimeters from an opening of a right ear canal of the user.

37. The apparatus according to claim 33, wherein said reference microphone is configured to be located, during use of the apparatus, at a front side of a midcoronal plane of a body of the user.

38. The apparatus according to claim 33, wherein said reference microphone is configured to be located, during use of the apparatus, closer to a midsagittal plane of a body of the user than to a midcoronal plane of the body of the user.

39. The apparatus according to claim 33, wherein a location of the reference microphone is invariant to rotation of the head.

40. The apparatus according to claim 33, wherein at least half of the energy of each of the left, right, and reference microphone signals is at frequencies not greater than fifteen hundred Hertz.

41. The apparatus according to claim 33, wherein said apparatus includes a rotation calculator configured to calculate a rotation of the head, based on said determined orientation.

42. The apparatus according to claim 33, wherein said apparatus includes:

an acoustic transfer function selector configured to select one among a set of acoustic transfer functions, based on said determined orientation; and

an audio processing stage configured to drive a pair of loudspeakers based on the selected acoustic transfer function.

43. The apparatus according to claim 42, wherein the selected acoustic transfer function includes a room impulse response.

44. The apparatus according to claim 42, wherein the selected acoustic transfer function includes a head-related transfer function.

45. The apparatus according to claim 42, wherein said audio processing stage is configured to perform a crosstalk cancellation operation that is based on the selected acoustic transfer function.

46. The apparatus according to claim 33, wherein said apparatus comprises:

a filter adaptation module configured to update an adaptive filtering operation, based on information from the signal produced by the left microphone and information from the signal produced by the right microphone; and

an audio processing stage configured to drive a pair of loudspeakers based on the updated adaptive filtering operation.

47. The apparatus according to claim 46, wherein the signal produced by the left microphone and the signal produced by the right microphone are produced in response to a sound field produced by the pair of loudspeakers.

48. The apparatus according to claim 42, wherein the pair of loudspeakers includes a left loudspeaker worn on the head to move with a left ear of the user, and a right loudspeaker worn on the head to move with a right ear of the user.

49. A non-transitory machine-readable storage medium comprising tangible features that when read by a machine cause the machine to:

calculate a first cross-correlation between a left microphone signal and a reference microphone signal;

calculate a second cross-correlation between a right microphone signal and the reference microphone signal; and

determine a corresponding orientation of a head of a user, based on information from the first and second calculated cross-correlations,

wherein the left microphone signal is based on a signal produced by a left microphone located at a left side of the head, the right microphone signal is based on a signal produced by a right microphone located at a right side of the head opposite to the left side, and the reference microphone signal is based on a signal produced by a reference microphone, and

wherein said reference microphone is located such that (A) as the head rotates in a first direction, a left distance between the left microphone and the reference microphone decreases and a right distance between the right microphone and the reference microphone increases and (B) as the head rotates in a second direction opposite to the first direction, the left distance increases and the right distance decreases.