Virtual sound sources and rendering techniques

Abstract

Several methods may include receiving one or more audio signals, estimating the direct sound level for each loudspeaker in a set of loudspeakers in a listening area, estimating the loudness of each loudspeaker in the listening area, and rendering one or more audio signals for playback through the set of loudspeakers. Rendering may include determining the relative activation of each loudspeaker for each audio signal, at least in part, based on the direct sound level estimation for each loudspeaker in the listening area. The combined level of activation across the loudspeakers may be at least in part based on the loudness estimation of each loudspeaker in the listening area.

Claims

1. Audio processing method: A step in which a control system receives audio data via an interface system, wherein the audio data includes one or more audio signals; The control system estimates the direct sound level of each loudspeaker in a set of loudspeakers in an audio environment and generates an estimated value of the direct sound level for each loudspeaker in a listening area, wherein the set of loudspeakers includes two or more loudspeakers; The control system estimates the loudness of each loudspeaker in the set of loudspeakers and generates an estimated loudness value for each loudspeaker in the listening area; The control system performs the steps of rendering each of the one or more audio signals contained in the audio data for playback through the set of loudspeakers, and generating the rendered audio signal. Includes, The rendering described above includes determining the relative activation of each loudspeaker for each audio signal, at least in part, based on an estimate of the direct sound level for each loudspeaker in the listening area. The combined activation level across the loudspeakers is at least partially based on the estimated loudness of each loudspeaker in the listening area. method.

2. The method according to claim 1, wherein the estimated direct sound level is calculated, at least in part, as a function of the distance of each loudspeaker to the listening area.

3. The method according to claim 2, wherein the estimated value of the direct sound level is calculated from a formula for direct sound intensity that is proportional to 1 divided by the square of the distance.

4. The method according to claim 1, wherein the direct sound level is estimated at least in part from one or more estimated impulse responses of each loudspeaker in the listening area.

5. The method according to any one of claims 1 to 4, wherein the estimation of the direct sound level is performed in at least two frequency bands.

6. The method according to any one of claims 1 to 5, wherein the audio data includes associated spatial data, the spatial data indicates an intended perceived spatial location corresponding to an audio signal, and the rendering includes determining the relative activation of each loudspeaker to achieve the intended perceived spatial location indicated by the spatial data.

7. The method according to claim 6, wherein the intended perceived spatial location is indicated by audio object metadata, or can be derived from an audio format corresponding to a spherical harmonic-based sound field representation, or corresponds to a channel in a channel-based audio format.

8. The method according to claim 7, wherein the spherical harmonic-based sound field representation is based on higher-order ambisonics (HOA).

9. The method according to any one of claims 1 to 8, wherein the direct sound level and loudness are estimated, at least in part, as a function of the distance from each loudspeaker to the listening area.

10. The method according to claim 9, wherein the loudness is estimated from a whole-tone intensity formula in which the result is proportional to the sum of 1 divided by the square of the distance and 1 divided by the square of the critical distance, where the critical distance is the distance from the loudspeaker at which the intensity of the direct sound is substantially equal to the intensity of the reverberation.

11. The method according to claim 1, wherein the direct sound level and loudness are estimated, at least in part, from one or more estimated impulse responses of each loudspeaker in the listening area.

12. The method according to any one of claims 1 to 11, wherein the loudness estimation is performed in at least two frequency bands.

13. The method according to any one of claims 1 to 12, wherein at least one subset of two or more audio signals corresponds to a common audio signal, relative activation across the subsets is maintained, while the combined level of activation across the subsets is based on an estimate of the loudness of each loudspeaker in the listening area.

14. The method according to claim 13, wherein the at least one subset of two or more audio signals is generated by extracting common signal components from two or more of the one or more audio signals.

15. The method according to any one of claims 1 to 14, wherein the first loudspeaker of the set of loudspeakers is located at a first distance from the listening area, and the second loudspeaker of the set of loudspeakers is located at a second distance from the listening area, and the first distance is different from the second distance.

16. The method according to any one of claims 1 to 15, further comprising the step of providing the rendered audio signal to the set of loudspeakers.

17. An apparatus configured to perform the method described in any one of claims 1 to 16.

18. A system configured to perform the method described in any one of claims 1 to 16.

19. One or more computer-readable, non-temporary media on which instructions for performing the method according to any one of claims 1 to 16 are encoded.

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