Acoustic radiation control method and system

Patent metadata

Field	Value
Publication number	US-11044552-B2
Application number	US-201716638021-A
Country	US
Kind code	B2
Filing date	Aug 31, 2017
Priority date	Aug 31, 2017
Publication date	Jun 22, 2021
Grant date	Jun 22, 2021

Abstract

Acoustic radiation control method and system are provided. The acoustic radiation control method includes: configuring a speaker array; obtaining transfer functions of speakers in the speaker array based on configuration of the speaker array and directivity of the speakers; obtaining, based on the transfer functions of the speakers, source strength of the speakers which enables acoustic radiation of the speaker array in a first zone greater than acoustic radiation of the speaker array in a second zone; and applying the source strength of the speakers to the speaker array. By the method, acoustic radiation may be controlled more accurately, a sidelobe level may be constrained more effectively, and the number of speakers in the speaker array may be reduced.

First claim

The invention claimed is:

1. An acoustic radiation control method, comprising:
configuring a speaker array;
obtaining transfer functions of speakers in the speaker array based on a configuration of the speaker array and a measured directivity of the speakers, comprising the steps of:
calculating an original transfer function of each speaker in the speaker array;
measuring a directivity of each speaker in the speaker array, the measured directivity of each speaker in the speaker array represents an acoustic radiation of the speaker at different optimized positions; and
taking a product of the original transfer function and the directivity of each speaker in the speaker array;

obtaining, based on the transfer functions of the speakers, a source strength of the speakers which enables an acoustic radiation of the speaker array in a first zone greater than an acoustic radiation of the speaker array in a second zone; and
applying the source strength of the speakers to the speaker array.

2. The acoustic radiation control method according to claim 1 , wherein the configuration of the speaker array comprises a number of the speakers in the speaker array, a facing direction of the speakers in the speaker array and a spacing between adjacent speakers in the speaker array.

3. The acoustic radiation control method according to claim 1 , wherein the original transfer functions of the speakers in the speaker array are determined based on the configuration of the speaker array and the directivity of the speakers in the speaker array is are determined based on the configuration of the speaker array.

4. The acoustic radiation control method according to claim 3 , wherein the original transfer functions of the speakers and the directivity of the speakers are determined further based on frequency of an input audio source provided to the speaker array.

5. The acoustic radiation control method according to claim 4 , wherein the transfer function of each speaker in the speaker array is calculated based on Equation (1),

H
D

⁡

(

r
n

)

=

e

-
jk

⁢


r



r


⁢

D
⁡

(

θ
,
k

)

,

Equation
⁢

⁢

(
1
)

where

e

-
jk

⁢


r



r


is an original transfer function of the n th speaker in the speaker array, D(θ, k) is the directivity of the n th speaker at wave number k, k=2πf/c, f is frequency of an input audio source, c is speed of sound, r is a vector representing a position relation between an optimized position and a center of the n th speaker, and θ is an angle between a direction from a center of the n th speaker to the optimized position and a facing direction of the n th speaker.

6. The acoustic radiation control method according to claim 1 , wherein the source strength of the speakers obtained based on the transfer functions of the speakers maximizes a ratio of an acoustic radiation of the speaker array in the first zone to an acoustic radiation of the speaker array in the second zone.

7. The acoustic radiation control method according to claim 6 , wherein the source strength of the speakers is obtained using an acoustic contrast control method based on the transfer functions of the speakers.

8. The acoustic radiation control method according to claim 1 , wherein applying the source strength of the speakers to the speaker array comprises:
performing the inverse Fourier transform to the source strength of the speakers to obtain coefficients of a Finite Impulse Response (FIR) filter, wherein the FIR filter is applied to an input audio source provided to the speaker array.

9. An acoustic radiation control system, comprising:
a speaker array; and
a processor configured to:
obtain transfer functions of speakers in the speaker array based on a configuration of the speaker array and a directivity of the speakers, comprising the steps of:
calculating an original transfer function of each speaker in the speaker array;
measuring a directivity of each speaker in the speaker array, the measured directivity of each speaker in the speaker array represents an acoustic radiation of the speaker at different optimized positions; and
taking a product of the original transfer function and the directivity of each speaker in the speaker array;

obtain, based on the transfer functions of the speakers, a source strength of the speakers which enables an acoustic radiation of the speaker array in a first zone greater than an acoustic radiation of the speaker array in a second zone; and
apply the source strength of the speakers to the speaker array.

10. The acoustic radiation control system according to claim 9 , wherein the configuration of the speaker array comprises a number of the speakers in the speaker array, a facing direction of the speakers in the speaker array and a spacing between adjacent speakers in the speaker array.

11. The acoustic radiation control system according to claim 9 , wherein the processor is configured to determine the original transfer functions of each of the speakers based on the configuration of the speaker array and the directivity of each of the speakers based on the configuration of the speaker array.

12. T

Assignees

• Zheng Jianwen
• Harman Int Ind

Inventors

• Zheng Jianwen

Classifications

• H04S7/302

  Electronic adaptation of stereophonic sound system to listener position or orientation (H04S7/301 takes precedence) · CPC title

• H04S2420/01

  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 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

• H04R1/403 Primary

  loud-speakers · CPC title

• H04R5/02

  Spatial or constructional arrangements of loudspeakers · CPC title