There has recently been an increasing interest in the generation of a sound field that is audible in one spatial region and inaudible in an adjacent region. The method proposed here ensures the control of the amplitude and phase of multiple acoustic sources in order to maximize the acoustic energy difference between two adjacent regions while also ensuring that evenly distributed source strengths are used. The performance of the method proposed is evaluated by computer simulations and experiments with real loudspeaker arrays in the shape of a circle and a sphere. The proposed method gives an improvement in the efficiency of radiation into the space in which the sound should be audible, while maintaining the acoustic pressure difference between two acoustic spaces. This is shown to give an improvement of performance compared to the contrast control method previously proposed.

1.
P. A.
Nelson
and
S. J.
Elliott
,
Active Control of Sound
(
Academic
,
New York
,
1992
).
2.
D. L.
Smith
, “
Discrete-element line arrays—Their modelling and optimisation
,”
J. Audio Eng. Soc.
45
,
949
964
(
1997
).
3.
S.
Haykin
,
J. H.
Justice
,
N. L.
Owsley
,
J. L.
Yen
, and
A. C.
Kak
,
Array Signal Processing
(
Prentice-Hall
,
Englewood Cliffs, NJ
,
1985
).
4.
W. F.
Druyvesteyn
and
J.
Garas
, “
Personal sound
,”
J. Audio Eng. Soc.
45
,
685
701
(
1997
).
5.
J.
Choi
and
Y.
Kim
, “
Generation of an acoustically bright zone with an illuminated region using multiple sources
,”
J. Acoust. Soc. Am.
111
,
1695
1700
(
2002
).
6.
S. J.
Elliott
and
M.
Jones
, “
Active headrest for personal audio
,”
J. Acoust. Soc. Am.
119
,
2702
2709
(
2006
).
7.
J. -H.
Chang
,
C. -H.
Lee
,
J. -Y.
Park
, and
Y. -H.
Kim
, “
A realization of sound focused personal audio system using acoustic contrast control
,”
J. Acoust. Soc. Am.
125
,
2091
2097
(
2009
).
8.
C. W.
Therrien
,
Discrete Random Signals and Statistical Signal Processing
(
Prentice-Hall
,
Englewood Cliffs, NJ
,
1992
), pp.
685
695
.
9.
L.
Meirovitch
,
Principles and Techniques of Vibrations
(
Prentice-Hall
,
Englewood Cliffs, NJ
,
1997
), pp.
232
249
.
10.
J. S.
Arora
,
Introduction to Optimum Design
(
McGraw-Hill
,
New York
,
1989
), pp.
111
136
.
11.
G. W.
Stewart
,
Introduction to Matrix Computations
(
Academic
,
New York
,
1973
).
12.
J. -H.
Chang
,
M. -H.
Song
,
J. -Y.
Park
, and
Y. -H.
Kim
, “
How does the loudspeaker arrangement affect the personal audio system characteristics?
,”
Proceedings of ICSV16
, Krakow, Poland (
2009
).
13.
F. M.
Fazi
,
P. A.
Nelson
,
J. E. N.
Christensen
, and
J.
Seo
, “
Surround system based on three dimensional sound field reconstruction
,”
Proceedings of the 125th AES Convention, Audio Engineering Society
, San Francisco, CA (
2008
).
14.
F. M.
Fazi
,
V.
Brunel
,
P. A.
Nelson
,
L.
Hörchens
, and
J.
Seo
, “
Measurement and Fourier-Bessel analysis of loudspeaker radiation patterns using a spherical array of microphones
,”
Proceedings of the 124th AES Convention, Audio Engineering Society
, Amsterdam (
2008
).
15.
M. V.
Brunel
, “
Measurement and spherical harmonic representation of loudspeaker radiation pattern
,” MS thesis, ISVR,
University of Southampton
, Southampton, United Kingdom,
2007
.
You do not currently have access to this content.