Directional audio capture

Patent metadata

Field	Value
Publication number	US-9838784-B2
Application number	US-201514957447-A
Country	US
Kind code	B2
Filing date	Dec 2, 2015
Priority date	Dec 2, 2009
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

Systems and methods for improving performance of a directional audio capture system are provided. An example method includes correlating phase plots of at least two audio inputs, with the audio inputs being captured by at least two microphones. The method can further include generating, based on the correlation, estimates of salience at different directional angles to localize a direction of a source of sound. The method can allow providing cues to the directional audio capture system based on the estimates. The cues include attenuation levels. A rate of change of the levels of attenuation is controlled by attack and release time constants to avoid sound artifacts. The method also includes determining a mode based on an absence or presence of one or more peaks in the estimates of salience. The method also provides for configuring the directional audio capture system based on the determined mode.

First claim

What is claimed is:

1. A method for improving performance of a directional audio capture system, the method comprising:
correlating phase plots of at least two audio inputs;
generating, based on the correlation, estimates of salience at different directional angles to localize at least one direction associated with at least one source of a sound;
determining cues based on the estimates of salience;
providing the cues to the directional audio capture system; and
determining, based on the estimates of salience, a mode selected from a plurality of operational modes, the plurality of operational modes including a first operational mode wherein the at least one source of sound includes a single directional speech source.

2. The method of claim 1 , wherein the cues are used by the directional audio capture system to attenuate or amplify the at least two audio inputs at the different directional angles.

3. The method of claim 1 , wherein the cues include at least attenuation levels of the different directional angles.

4. The method of claim 1 , wherein the estimates of salience include a vector of saliences at directional angles from 0 to 360 in a plane parallel to a ground.

5. The method of claim 1 , wherein generating the cues includes mapping the different directional angles to relative levels of attenuation for the directional audio capture system.

6. The method of claim 5 , further comprising controlling the rate of changing the levels of attenuation in a real time by attack and release time constants to avoid sound artifacts.

7. The method of claim 1 , wherein the plurality of operational modes further includes a second operational mode wherein the at least one source of sound includes at least two single directional speech sources, and a third operational mode wherein the at least one source of sound includes a diffused noise source having no directional speech.

8. The method of claim 1 , wherein determining the mode is based on absence or presence of one or more peaks in the estimates of salience.

9. The method of claim 8 , further comprising configuring, based on the determined mode, the directional audio capture system.

10. The method of claim 1 , further comprising controlling a rate of switching between modes from the plurality of the operational modes in a real time by applying attack and release time constants.

11. The method of claim 1 , wherein the at least two audio inputs are captured by at least two microphones.

12. The method of claim 11 , wherein one of the at least two microphones is sealed better than other ones of the at least two microphones.

13. A system for improving performance of a directional audio capture system, the system comprising:
at least one processor; and
a memory communicatively coupled with the at least one processor, the memory storing instructions, which when executed by the at least one processor performs a method comprising:
correlating phase plots of at least two audio inputs;
generating, based on the correlation, estimates of salience at different directional angles to localize at least one direction associated with at least one source of a sound;
determining cues based on the estimates of salience;
providing the cues to the directional audio capture system; and
determining, based on absence or presence of one or more peaks in the estimates of salience, a mode selected from a plurality of operational modes, the plurality of operational modes including a first operational mode wherein the at least one source of sound includes a single directional speech source.

14. The system of claim 13 , wherein the cues are used by the directional audio capture system to attenuate or amplify the at least two audio inputs at the different directional angles.

15. The system of claim 13 , wherein the cues include at least attenuation levels for the different directional angles.

16. The system of claim 13 , wherein generating the cues includes mapping the different directional angles to relative levels of attenuation for the directional audio capture system.

17. The system of claim 13 , wherein the plurality of operational modes further includes a second operational mode wherein the at least one source of sound includes at least two single directional speech sources, and a third operational mode wherein the at least one source of sound includes a diffused noise source having no directional speech.

18. The system of claim 17 , further comprising:
configuring, based on the determined mode, the directional audio capture system, and
controlling a rate of switching between modes in a real time by applying attack and release time constants.

19. A non-transitory computer-readable storage medium having embodied thereon instructions, which when executed by at least one processor, perform steps of a method, the method comprising:
correlating phase plots of at least two audio inputs;
generating, based on the correlation, estimates of salience at different directional angles to localize at least one direction associated with at least one source of a sound;
determining cues based on the estimates of salience;
providing the cues to the directional audio capture system; and
determining, based on absence or presence of one or more peaks in the estimates of salience, a mode selected from a plurality of operational modes, the plurality of operational modes including a first operational mode wherein the at least one source of sound includes a single directional speech source.

Assignees

• Knowles Electronics Llc

Inventors

• Vallabhan Harinarayanan Erumbi
• Sakri Shailesh
• Avendano Carlos
• Solbach Ludger

Classifications

• H04R2430/21

  Direction finding using differential microphone array [DMA] · CPC title

• H04R2430/20

  Processing of the output signals of the acoustic transducers of an array for obtaining a desired directivity characteristic (H04R2203/12 takes precedence) · CPC title

• H04R2201/405

  Non-uniform arrays of transducers or a plurality of uniform arrays with different transducer spacing · CPC title

• H04M1/03

  Constructional features of telephone transmitters or receivers, e.g. telephone hand-sets · CPC title

• H04R3/005 Primary

  for combining the signals of two or more microphones (specially adapted for hearing aids H04R25/407) · CPC title