Speaker device and audio signal processing method

• US 10,038,963 B2
• Filed: 03/29/2017
• Issued: 07/31/2018
• Est. Priority Date: 08/19/2013
• Status: Active Grant

• Current Assignee: Yamaha Corporation
• Original Assignee: Yamaha Corporation
• Inventors: Katayama, Masaki, Takumai, Susumu, Imaoka, Keiichi
• Primary Examiner(s): Joshi, Sunita
• Application Number:
  US15/472,591
• Publication Number:
  US 20170201846A1
• Time in Patent Office: 489 Days
• Field of Search: 381 17, 381 231, 381300, 381309, 381 1, 381 23, 381 72, 381 18, 381 2, 381 22, 381 26, 381 27, 381 57, 381 61, 381 716
• CPC Class Codes: H04R 1/323 for loudspeakers H04R1/34 and H04R1/40 take precedence
• CPC Class Codes: H04R 1/326 for microphones H04R1/34 and H04R1/40 take precedence
• CPC Class Codes: H04R 2203/12 Beamforming aspects for stereophonic sound reproduction with loudspeaker arrays
• CPC Class Codes: H04R 2430/20 Processing of the output signals of the acoustic transducers of an array for obtaining a desired directivity characteristic H04R2203/12 takes precedence
• CPC Class Codes: H04R 29/002 Loudspeaker arrays
• CPC Class Codes: H04R 3/12 for distributing signals to two or more loudspeakers specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04R 5/02 Spatial or constructional arrangements of loudspeakers
• 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 2420/07 Synergistic effects of band splitting and sub-band processing
• CPC Class Codes: H04S 3/008 in which the audio signals are in digital form, i.e. employing more than two discrete digital channels data reduction aspects thereof based on psychoacoustics G10L19/02
• CPC Class Codes: H04S 7/30 Control circuits for electronic adaptation of the sound field
• CPC Class Codes: H04S 7/301 Automatic calibration of stereophonic sound system, e.g. with test microphone

Abstract

A speaker apparatus includes an input portion to which audio signals of a plurality of channels are input, a plurality of speakers, a directivity controlling portion that delays the audio signals of the plurality of channels input to the input portion and distributes the delayed audio signals to the plurality of speakers so that the plurality of speakers output a plurality of sound beams, and a localization adding portion that applies a filtering processing based on a head-related transfer function to at least one of the audio signals of the plurality of channels input to the input portion and inputs the processed audio signal to the plurality of speakers.

Claims

1. A speaker apparatus comprising:

an input portion to which audio signals of a plurality of channels are input;

a plurality of speakers;

at least one processor for executing stored instructions to;

delay at least one of the audio signals of the plurality of channels input to the input portion and distribute the delayed at least one audio signal to the plurality of speakers so that the plurality of speakers output a plurality of sound beams, wherein the plurality of sound beams are directed toward at least one focus position; and

apply a filtering processing based on a head-related transfer function to at least one of the audio signals of the plurality of channels input to the input portion and inputs the processed audio signal to the plurality of speakers,

wherein a virtual sound source, localized by the at least one of the audio signals of the plurality of channels to which the filtering processing based on the head-related transfer function, is applied so as to appear to emanate from a direction of the focus position at a listening point,

wherein the delayed audio signal and the processed audio signal are of a same channel, and

wherein the virtual sound source and the plurality of sound beams are simultaneously formed.

2. The speaker apparatus according to claim 1, wherein the at least one processor further

adjusts and sets levels of the processed audio signals of the respective channels and levels of the audio signals of the sound beams of the respective channels.

3. The speaker apparatus according to claim 2, further comprising:

a microphone installed in the listening position; and

wherein the at least one processor further

detects a level of the sound beam of each channel reaching the listening position,

inputs a test signal to cause the plurality of speakers to output a test sound beam, measures a level of the test sound beam input to the microphone; and

sets the levels of the processed audio signals of the respective channels and levels of the audio signals of the sound beams of the respective channels a result of the measurement.

4. The speaker apparatus according to claim 1, wherein at least one processor further

outputs an audio signal of one channel as a plurality of sound beams for localizing a phantom sound source, and

sets the direction of the virtual sound source based on the head-related transfer function in a direction corresponding to a localization direction of the phantom sound source.

5. The speaker apparatus according to claim 1, wherein at least one processor further

divides each of the audio signals input to the input portion into a high frequency component and a low frequency component, and output the divided signals,

wherein the plurality of speakers include a speaker array to which the audio signals from the delayed and distributed sound are input, and a stereo speaker to which the audio signals from the filter processed sound are input;

wherein the high frequency component of the audio signal output from the divided signals is input for delay and distribution; and

wherein the low frequency component of the audio signal output from the divided signals is input to the stereo speaker.

6. A method for audio signal processing, the method comprising the acts of:

delaying at least one audio signal of audio signals of a plurality of channels input to an input portion of a speaker apparatus;

distributing the delayed at least one audio signal to a plurality of speakers so that the plurality of speakers output a plurality of sound beams, wherein the plurality of sound beams are directed toward at least one focus position;

applying a filtering processing based on a head-related transfer function to the at least one of the audio signals of the plurality of channels input to the input portion;

inputting the processed audio signal to the plurality of speakers; and

applying a virtual sound source, localized by the at least one of the audio signals of the plurality of channels to which the filtering processing based on the head-related transfer function, so as to appear to emanate from a direction of the focus position at a listening point,

wherein the delayed audio signal and the processed audio signal are of a same channel, and

wherein the virtual sound source and the plurality of sound beams are simultaneously formed.

7. The method according to claim 6, further comprising the act of adjusting and setting levels of the processed audio signals of the respective channels and levels of the audio signals of the sound beams of the respective channels.

8. The method according to claim 7 further comprising the acts of:

detecting a level of the sound beam of each channel reaching the listening position;

inputting a test signal to cause the plurality of speakers to output a test sound beam;

measuring a level of the test sound beam input to a microphone installed in the listening position; and

setting the levels of the processed audio signals of the respective channels and levels of the audio signals of the sound beams of the respective channels a result of the measurement.

9. The method according to claim 6, further comprising the acts of:

outputting an audio signal of one channel as a plurality of sound beams for localizing a phantom sound source; and

setting the direction of the virtual sound source based on the head-related transfer function in a direction corresponding to a localization direction of the phantom sound source.

10. The method according to claim 6, further comprising the acts of:

dividing each of the audio signals input to the input portion into a high frequency component and a low frequency component; and

outputting the divided signals,

wherein the plurality of speakers include a speaker array to which the audio signals from the delayed and distributed sound are input, and a stereo speaker to which the audio signals from the filter processed sound are input,

wherein the high frequency component of the audio signal output from the divided signals is input for delay and distribution, and

wherein the low frequency component of the audio signal output from the divided signals is input to the stereo speaker.