Technique for localizing sound source

Patent metadata

Field	Value
Publication number	US-9319785-B2
Application number	US-201213424869-A
Country	US
Kind code	B2
Filing date	Mar 20, 2012
Priority date	Dec 9, 2011
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

Disclosed is a technique for localizing a sound source. In the technique, a sound pressure signal measured by microphones is acquired using a spherical microphone array sensor where the microphones are fixedly arranged on a surface of a spherical body. A sound pressure distribution on the surface of the spherical body is obtained by a controller from a sound pressure calculation formula for calculating a sound pressure at a certain location of a spherical surface using the sound pressure signal measured by the microphones as an input value. A location of the sound source is estimated from the obtained sound pressure distribution.

First claim

What is claimed is:

1. A method for localizing a sound source, comprising:
acquiring, by a controller, a sound pressure signal measured by microphones, using a spherical microphone array sensor wherein the microphones are fixedly arranged on a surface of a spherical body;
obtaining a sound pressure distribution on the surface of the spherical body from a sound pressure calculation formula for calculating a sound pressure at a certain location of a spherical surface using the sound pressure signal measured by the microphones as an input value; and
estimating a location of the sound source from the obtained sound pressure distribution,
wherein, from Equation (1) below the sound pressure calculation formula is obtained by meeting r=a (here, a is a radius of the spherical body) and limiting a sound field distribution order n to a maximum order N of Equation (2) below that considers a total number of microphones;

p
⁡

(

r
,
θ
,
ϕ

)

=

∑

n
=
0

∞

⁢

j
n

⁡

(
kr
)

j
n

⁡

(
ka
)

⁢

∑

m
=

-
n

n

⁢

Y
n
m

⁡

(

θ
,
ϕ

)

⁢

∫
0

2
⁢
π

⁢

∫
0
π

⁢

p
⁡

(

a
,

θ
0

,

ϕ
o

)

⁢

Y
n
m

⁡

(

θ
0

,

ϕ
0

)

*

⁢
sin
⁢

⁢
θ
⁢

ⅆ
θ

⁢

ⅆ
ϕ

(
1
)

where j n (kr) is a spherical Bessel function, n is an order of sound field distribution, m={−n, −n−1, . . . , 0, 1, . . . , n−1, n}, Y n m (θ,φ) are spherical harmonic functions, r denotes a radius of a sphere, θ denotes a horizontal angle of a spherical coordinate, φ denotes a vertical angle of the spherical coordinate, θ 0 and φ o denote the horizontal angle and the vertical angle of microphone location respectively, and p(a,θ 0 ,φ o ) denotes a sound pressure mea

Assignees

• Lee Jong Hyun
• Lee Myung Han
• Cho Mun Hwan
• Ih Kang Duck
• Hyundai Motor Co Ltd

Inventors

• Lee Jong Hyun
• Lee Myung Han
• Cho Mun Hwan
• Ih Kang Duck

Classifications

• H04R2499/13

  Acoustic transducers and sound field adaptation in vehicles · CPC title

• G01S3/808

  using transducers spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems · CPC title

• H04R2201/401

  2D or 3D arrays of transducers · CPC title

• H04R1/406

  microphones · CPC title

• H04R3/005 Primary

  for combining the signals of two or more microphones (specially adapted for hearing aids H04R25/407) · CPC title