METHOD AND APPARATUS FOR ESTIMATING TALKER DISTANCE

• US 20160057522A1
• Filed: 08/19/2014
• Published: 02/25/2016
• Est. Priority Date: 08/19/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Johnson, Martin E., Family, Afrooz, Choisel, Sylvain J.
• Granted Patent: US 9,769,552 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01S 3/803 using amplitude comparison of signals derived from receiving transducers or transducer systems having differently-oriented directivity characteristics
• CPC Class Codes: G01S 5/28 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
• CPC Class Codes: H04R 1/08 Mouthpieces; Microphones; Attachments therefor
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

An audio capture device generates two microphone beam patterns with different directivity indices. The audio capture device may determine the position of a user relative to the audio capture device based on sounds detected by the separate microphone beam patterns. Accordingly, the audio capture device allows the determination of the position of the user without the complexity and cost of using a dedicated listening device and/or a camera. In particular, the audio capture device does not need to be immediately proximate to the user (e.g., held near the ear of the user) and may be used to immediately provide other services to the user (e.g., audio/video playback, telephony functions, etc.). The position of the user may include the measured distance between the audio capture device and the user, the proximity of the user relative to another device/object, and/or the orientation of the user relative to the audio capture device.

Claims

1. A method for determining positioning of a user, comprising:

detecting, by a first microphone beam pattern generated by an audio capture device, sound produced by the user;

detecting, by a second microphone beam pattern generated by the audio capture device, the sound produced by the user, wherein the first beam pattern has a first directivity index and the second beam pattern has a second directivity index that is different from the first directivity index; and

determining the positioning of the user based on the sound detected by the first microphone beam pattern and the sound detected by the second microphone beam pattern.

2. The method of claim 1, wherein the positioning of the user describes the distance between the user and the audio capture device.

3. The method of claim 1, wherein the positioning of the user describes the proximity of the user relative to one or more objects.

4. The method of claim 1, wherein the positioning of the user describes whether the user is speaking directly at the audio capture device.

5. The method of claim 1, wherein the positioning of the user is determined for separate blocks of the sound produced by the user over time, the method further comprising:

smoothing the positioning values generated over time to determine a smoothed positioning value.

6. The method of claim 1, further comprising:

determining a reverberation time of a listening area in which the user and the audio capture device are located;

determining a geometric volume of the listening area;

determining a first power level of a signal corresponding to the first microphone beam pattern; and

determining a second power level of a signal corresponding to the second microphone beam pattern,

wherein the positioning of the user is determined based on the reverberation time of the listening area, the geometric volume of the listening area, a directivity index of the sound emitted by the user, the first power level, and the second power level.

7. The method of claim 2, further comprising:

determining whether the audio capture device is closer to the user than another device based on the determined positioning of the user; and

processing, by the audio capture device, the sound detected from the user in response to determining that the user is closer to the audio capture device than another device.

8. The method of claim 4, further comprising:

processing, by the audio capture device, the sound detected from the user in response to determining that the user is speaking directly at the audio capture device based on the determined positioning of the user.

9. The method of claim 1, further comprising:

selecting the first microphone beam from a set of microphone beams generated by the audio capture device based on powers of signals generated by each microphone beam in the set of microphone beams, wherein the microphone beam in the set of microphone beams with the highest power level is selected as the first microphone beam.

10. A method for determining positioning of a user, comprising:

detecting, by a first microphone of an audio capture device, sound produced by the user;

detecting, by a second microphone of the audio capture device, the sound produced by the user, wherein the first microphone has a first directivity index and the second microphone has a second directivity index that is different from the first directivity index and the first and second directivity indices are based on sound diffraction around a cabinet in which the first and second microphones are placed; and

determining the positioning of the user based on the sound detected by the first microphone and the sound detected by the second microphone.

11. The method of claim 10, further comprising:

determining a reverberation time of a listening area in which the user and the audio capture device are located;

determining a geometric volume of the listening area;

determining a first power level of a signal corresponding to the first microphone; and

determining a second power level of a signal corresponding to the second microphone,

wherein the positioning of the user is determined based on the reverberation time of the listening area, the geometric volume of the listening area, a directivity index of the sound emitted by the user, the first power level, and the second power level.

12. A system for determining positioning of a user, comprising:

an audio capture device to generate a first microphone beam pattern and a second microphone beam pattern, wherein the first microphone beam pattern detects sound produced by the user and the second microphone beam pattern detects the sound produced by the user, wherein the first microphone beam pattern has a first directivity index and the second microphone beam pattern has a second directivity index that is different from the first directivity index; and

a distance estimation unit to determine the positioning of the user based on the sound detected by the first microphone beam pattern and the sound detected by the second microphone beam pattern.

13. The system of claim 12, wherein the positioning of the user describes the distance between the user and the audio capture device.

14. The system of claim 12, wherein the positioning of the user describes the proximity of the user relative to one or more objects.

15. The system of claim 12, wherein the positioning of the user describes whether the user is speaking directly at the audio capture device.

16. The system of claim 12, wherein the positioning of the user is determined for separate blocks of the sound produced by the user over time and the distance estimation unit to smooth the positioning values generated over time to determine a smoothed positioning value.

17. The system of claim 12, further comprising:

a reverberation time unit to determine a reverberation time of a listening area in which the user and the audio capture device are located;

a listening area volume unit to determine a geometric volume of the listening area; and

a power level unit to determine a first power level of a signal corresponding to the first microphone beam pattern and a second power level of a signal corresponding to the second microphone beam pattern,

wherein the positioning of the user is determined based on the reverberation time of the listening area, the geometric volume of the listening area, a directivity index of the sound emitted by the user, the first power level, and the second power level.

18. The system of claim 13, wherein the audio capture device processes the sound detected from the user in response to determining that the user is closer to the audio capture device than another device.

19. The system of claim 13, wherein the audio capture device processes the sound detected from the user in response to determining that the user is speaking directly at the audio capture device based on the determined positioning of the user.

20. The system of claim 12, wherein the audio capture device produces a set of microphone beams, wherein the distance estimation unit selects the first microphone beam from a set of microphone beams generated by the audio capture device based on powers of signals generated by each microphone beam in the set of microphone beams, wherein the microphone beam in the set of microphone beams with the highest power level is selected as the first microphone beam.