Focusing on a Portion of an Audio Scene for an Audio Signal

• US 20090116652A1
• Filed: 11/01/2007
• Published: 05/07/2009
• Est. Priority Date: 11/01/2007
• Status: Active Grant

• Current Assignee: Piece Future Pte., Ltd.
• Original Assignee: Nokia Corporation
• Inventors: Kirkeby, Ole, Virolainen, Jussi
• Granted Patent: US 8,509,454 B2
• Time in Patent Office: Days
• US Class Current: 381/1
• CPC Class Codes: H04S 2400/11 Positioning of individual sound objects, e.g. moving airplane, within a sound field H04S2420/13 takes precedence
• CPC Class Codes: H04S 2400/15 Aspects of sound capture and related signal processing for recording or reproduction
• CPC Class Codes: H04S 2420/01 Enhancing the perception of the sound image or of the spatial distribution using head related transfer functions [HRTF's] or equivalents thereof, e.g. interaural time difference [ITD] or interaural level difference [ILD]
• CPC Class Codes: H04S 2420/11 Application of ambisonics in stereophonic audio systems
• CPC Class Codes: H04S 3/00 Systems employing more than two channels, e.g. quadraphonic H04S5/00, H04S7/00 take precedence
• CPC Class Codes: H04S 7/303 Tracking of listener position or orientation

Abstract

Aspects of the invention provide methods, computer-readable media, and apparatuses for spatially manipulating sound that is played back to a listener over a set of output transducers, e.g., headphones. The listener can direct spatial attention to focus on a portion of an audio scene, analogous to a magnifying glass being used to pick out details in a picture. An input multi-channel audio signal that is generated by audio sources is obtained, and directional information is determined for each of the audio sources. The user provides a desired direction of spatial attention so that audio processing can focus on the desired direction and render a corresponding multi-channel audio signal to the user. A region of an audio scene is expanded around the desired direction while the audio scene is compressed in another portion of the audio scene.

Claims

1. A method comprising:

obtaining an input multi-channel audio signal that is generated by a plurality of audio sources;

determining directional information for each of the plurality of audio sources;

obtaining at least one desired direction of spatial attention;

focusing on the input multi-channel audio signal in the at least one desired direction to form an output multi-channel audio signal; and

rendering the output multi-channel audio signal to a user.

2. The method of claim 1, further comprising:

expanding a first region of an audio scene around the at least one desired direction.

3. The method of claim 2, further comprising:

compressing a second region of the audio scene.

4. The method of claim 3, further comprising:

re-mapping input azimuth values to output azimuth values, the output azimuth values being different from the input azimuth values.

5. The method of claim 4, further comprising:

utilizing a remapping function to re-map the input azimuth values.

6. The method of claim 5, the re-mapping function being characterized by a non-linearity and having a derivative greater than one for a subset of the input azimuth values.

7. The method of claim 1, further comprising:

preserving an overall loudness of the input multi-channel audio signal when rendering the output multi-channel audio signal.

8. The method of claim 2, further comprising:

amplifying the input multi-channel audio signal about the first region of the audio scene.

9. The method of claim 1, the output multi-channel audio signal comprising a binaural audio signal.

10. The method of claim 1, the at least one desired direction of spatial attention being obtained from a headtracker that is fastened to the user.

11. An apparatus comprising:

an input module configured to obtain an input multi-channel audio signal that is generated by a plurality of audio sources;

a spatial content analyzer configured to determine directional information for each of the plurality of audio sources;

an input device configured to obtain a desired direction of spatial attention;

an audio processing module configured to focus on the input multi-channel audio signal in the desired direction to form a focused multi-channel audio signal; and

a synthesizer configured to render the focused multi-channel audio signal to a user.

12. The apparatus of claim 11, the audio processing module further configured to expand a first region of an audio scene around the desired direction and to compress a second region of the audio scene.

13. The apparatus of claim 12, the audio processing module further configured to re-map input azimuth values to output azimuth values, the output azimuth values being different from the input azimuth values.

14. The apparatus of claim 13, the audio processing module further configured to utilize a re-mapping function to re-map the input azimuth values.

15. The apparatus of claim 14, the audio processing module further configured to utilize the re-mapping function, wherein the re-mapping function is characterized by a non-linearity and having a derivative greater than one for a subset of the input azimuth values.

16. A computer-readable medium having computer-executable instructions comprising:

obtaining an input multi-channel audio signal that is generated by a plurality of audio sources;

determining directional information for each of the plurality of audio sources;

obtaining a desired direction of spatial attention;

focusing on the input multi-channel audio signal in the desired direction to form an output multi-channel audio signal; and

rendering the output multi-channel audio signal to a user.

17. The computer-readable medium of claim 16, further comprising:

expanding a first region of an audio scene around the desired direction; and

compressing a second region of the audio scene.

18. The computer-readable medium of claim 17, further comprising:

re-mapping input azimuth values to output azimuth values, the output azimuth values being different from the input azimuth values.

19. The computer-readable medium of claim 18, further comprising:

utilizing a remapping function to re-map the input azimuth values, the re-mapping function being characterized by a non-linearity and having a derivative greater than one for a subset of the input azimuth values.

20. An apparatus comprising:

means for obtaining an input multi-channel audio signal that is generated by a plurality of audio sources;

means for determining directional information for each of the plurality of audio sources;

means for obtaining a desired direction of spatial attention;

means for focusing on the input multi-channel audio signal in the desired direction to form an output multi-channel audio signal; and

means for rendering the output multi-channel audio signal to a user.

21. The apparatus of claim 20, further comprising:

means for expanding a first region of an audio scene around the desired direction; and

means for compressing a second region of the audio scene.

22. The apparatus of claim 21, further comprising:

means for re-mapping input azimuth values to output azimuth values, the output azimuth values being different from the input azimuth values.

23. An integrated circuit comprising:

an input component configured to obtain an input multi-channel audio signal that is generated by a plurality of audio sources;

a spatial content analyzing component configured to determine directional information for each of the plurality of audio sources;

an input component configured to obtain a desired direction of spatial attention;

an audio processing component configured to focus on the input multi-channel audio signal in the desired direction to form a focused multi-channel audio signal; and

a synthesizing component configured to render the focused multi-channel audio signal to a user.

24. The integrated circuit of claim 23, the audio processing component further configured to expand a first region of an audio scene around the desired direction and to compress a second region of the audio scene.

25. The integrated circuit of claim 24, the audio processing component further configured to re-map input azimuth values to output azimuth values, the output azimuth values being different from the input azimuth values.