AUDIO PROCESSING METHOD AND AUDIO PROCESSING APPARATUS

• US 20190020968A1
• Filed: 09/19/2018
• Published: 01/17/2019
• Est. Priority Date: 03/23/2016
• Status: Active Grant

• Current Assignee: Yamaha Corporation
• Original Assignee: Yamaha Corporation
• Inventors: SUENAGA, Tsukasa, SHIRAKIHARA, Futoshi
• Granted Patent: US 10,708,705 B2
• Time in Patent Office: Days
• CPC Class Codes: H04S 1/007 in which the audio signals are in digital form data reduction aspects thereof based on psychoacoustics G10L19/02
• CPC Class Codes: H04S 2400/01 Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved
• 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 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 3/02 of the matrix type, i.e. in which input signals are combined algebraically, e.g. after having been phase shifted with respect to each other
• CPC Class Codes: H04S 7/303 Tracking of listener position or orientation

Abstract

An audio processing apparatus has a setting processor that sets a size of a virtual sound source; and a signal processor that generates an audio signal by imparting to an audio signal a plurality of head-related transfer characteristics. The plurality of head-related transfer characteristics corresponds to respective points within a range that accords with the size set by the setting processor from among a plurality of points, with each point having a different position relative to a listening point.

Claims

1. An audio processing method comprising:

setting a size of a virtual sound source; and

generating a second audio signal by imparting to a first audio signal a plurality of head-related transfer characteristics, wherein the plurality of head-related transfer characteristics corresponds to respective points within a range that accords with the set size from among a plurality of points, with each point having a different position relative to a listening point.

2. The audio processing method according to claim 1,

wherein the generation of the second audio signal includes:

setting the range according to the size of the virtual sound source;

synthesizing the plurality of head-related transfer characteristics corresponding to the respective points within the set range to generate a synthesized head-related transfer characteristic; and

generating the second audio signal by imparting the synthesized head-related transfer characteristic to the first audio signal.

3. The audio processing method according to claim 2, further comprising setting a position of the virtual sound source,

wherein the setting of the range includes setting the range according to the size and the position of the virtual sound source.

4. The audio processing method according to claim 2,

wherein the synthesizing of the plurality of head-related transfer characteristics includes weight averaging the plurality of head-related transfer characteristics by using weighted values, wherein each of the weighted values is set in accordance with a position of each point within the range.

5. The audio processing method according to claim 2,

wherein the setting of the range includes setting the range by perspectively projecting the virtual sound source onto a reference plane including the plurality of points, with the center of the projection being the listening point or an ear position corresponding to the listening point.

6. The audio processing method according to claim 1, comprising:

setting the range individually for each of a right ear and a left ear; and

generating the second audio signal for a right channel by imparting to the first audio signal the plurality of head-related transfer characteristics for the right ear, wherein the plurality of head-related transfer characteristics corresponds to respective points within the range set with regard to the right ear, and generating the second audio signal for a left channel by imparting to the first audio signal the plurality of head-related transfer characteristics for the left ear, wherein the plurality of head-related transfer characteristics corresponds to respective points within the range set with regard to the left ear.

7. The audio processing method according to claim 1, comprising:

setting the range, which is common for a right ear and a left ear; and

generating the second audio signal for a right channel by imparting to the first audio signal the plurality of head-related transfer characteristics for the right ear, wherein the plurality of head-related transfer characteristics corresponds to respective points within the range, and generating the second audio signal for a left channel by imparting to the first audio signal the plurality of head-related transfer characteristics for the left ear, wherein the plurality of head-related transfer characteristics corresponds to respective points within the range.

8. The audio processing method according to claim 2,

wherein the generation of the second audio signal includes correcting, for each of the plurality of head-related transfer characteristics corresponding to the respective points within the range, a delay amount of each head-related transfer characteristic according to a distance between each point and an ear location at the listening point;

and

wherein the synthesizing of the plurality of head-related transfer characteristics includes synthesizing the corrected head-related transfer characteristics.

9. An audio processing apparatus comprising:

at least one processor configured to execute stored instructions to;

set a size of a virtual sound source; and

generate a second audio signal by imparting to a first audio signal a plurality of head-related transfer characteristics, wherein the plurality of head-related transfer characteristics corresponds to respective points within a range that accords with the set size from among a plurality of points, with each point having a different position relative to a listening point.

10. The audio processing apparatus according to claim 9,

wherein the at least one processor is configured to:

in generating the second audio signal,

set the range according to the size of the virtual sound source;

synthesize the plurality of head-related transfer characteristics corresponding to the respective points within the set range to generate a synthesized head-related transfer characteristic; and

generate the second audio signal by imparting the synthesized head-related transfer characteristic to the first audio signal.

11. The audio processing apparatus according to claim 10,

wherein the at least one processor is further configured to set a position of the virtual sound source, and

wherein the at least one processor is configured to set the range according to the size and the position of the virtual sound source.

12. The audio processing apparatus according to claim 10,

wherein the at least one processor is configured to, in synthesizing the plurality of head-related transfer characteristics, weight average the plurality of head-related transfer characteristics by using weighted values, wherein each of the weighted values is set in accordance with a position of each point within the range.

13. The audio processing apparatus according to claim 10,

wherein the at least one processor is configured to set the range by perspectively projecting the virtual sound source onto a reference plane including the plurality of points, with the center of the projection being the listening point or an ear position corresponding to the listening point.

14. The audio processing apparatus according to claim 9,

wherein the at least one processor is configured to:

set the range individually for each of a right ear and a left ear; and

generate the second audio signal for a right channel by imparting to the first audio signal the plurality of head-related transfer characteristics for the right ear, wherein the plurality of head-related transfer characteristics corresponds to respective points within the range set with regard to the right ear, and generate the second audio signal for a left channel by imparting to the first audio signal the plurality of head-related transfer characteristics for the left ear, wherein the plurality of head-related transfer characteristics corresponds to respective points within the range set with regard to the left ear.

15. The audio processing apparatus according to claim 9,

wherein the at least one processor is configured to:

set the range, which is common for a right ear and a left ear; and

generate the second audio signal for a right channel by imparting to the first audio signal the plurality of head-related transfer characteristics for the right ear, wherein the plurality of head-related transfer characteristics corresponds to respective points within the range, and generate the second audio signal for a left channel by imparting to the first audio signal the plurality of head-related transfer characteristics for the left ear, wherein the plurality of head-related transfer characteristics corresponds to respective points within the range.

16. The audio processing apparatus according to claim 10,

wherein the at least one processor is configured to:

in generating the second audio signal, correct, for each of the plurality of head-related transfer characteristics corresponding to the respective points within the range, a delay amount of each head-related transfer characteristic according to a distance between each point and an ear location at the listening point; and

in synthesizing the plurality of head-related transfer characteristics, synthesize the corrected head-related transfer characteristics.