When presented with a spatially discordant auditory-visual stimulus, subjects sometimes perceive the sound and the visual stimuli as coming from the same location. Such a phenomenon is often referred to as perceptual fusion or ventriloquism, as it evokes the illusion created by a ventriloquist when his voice seems to emanate from his puppet rather than from his mouth. While this effect has been extensively examined in the horizontal plane and to a lesser extent in distance, few psychoacoustic studies have focused on elevation. In the present experiment, sequences of a man talking were presented to subjects. His voice could be reproduced on different loudspeakers, which created disparities in both azimuth and elevation between the sound and the visual stimuli. For each presentation, subjects had to indicate whether the voice seemed to emanate from the mouth of the actor or not. Results showed that ventriloquism could be observed with larger audiovisual disparities in elevation than in azimuth.

1.
Agganis
,
B. T.
,
Muday
,
J. A.
, and
Schirillo
,
J. A.
(
2010
). “
Visual biasing of auditory localization in azimuth and depth
,”
Percept. Mot. Skills
111
,
872
892
.
2.
Alais
,
D.
, and
Burr
,
D.
(
2004
). “
The ventriloquist effect results from near-optimal bimodal integration
,”
Curr. Biol.
14
,
257
262
.
3.
André
,
C.
,
Corteel
,
E.
,
Embrechts
,
J.-J.
,
Verly
,
J.
, and
Katz
,
B. F. G.
(
2014
). “
Subjective evaluation of the audiovisual spatial congruence in the case of stereoscopic-3D video and wave field synthesis
,”
Int. J. Hum.-Comput. St.
72
,
23
32
.
4.
Ashmead
,
D. H.
,
Leroy
,
D.
, and
Odom
,
R. D.
(
1990
). “
Perception of the relative distances of nearby sound sources
,”
Percept. Psychophys.
47
,
326
331
.
5.
Battaglia
,
P.
,
Jacobs
,
R.
, and
Aslin
,
R.
(
2003
). “
Bayesian integration of visual and auditory signals for spatial localization
,”
J. Opt. Soc. Am.
20
,
1391
1396
.
6.
Bermant
,
R. I.
, and
Welch
,
R. B.
(
1976
). “
Cross-modal bias and perceptual fusion with auditory-visual spatial discordance
,”
Percept. Mot. Skills
43
,
487
493
.
7.
Bertelson
,
P.
, and
Aschersleben
,
G.
(
1998
). “
Bayesian integration of visual and auditory signals for spatial localization
,”
Psychon. Bull. Rev.
5
,
482
489
.
8.
Bertelson
,
P.
, and
Radeau
,
M.
(
1981
). “
Cross-modal bias and perceptual fusion with auditory-visual spatial discordance
,”
Percept. Psychophys.
29
,
578
584
.
9.
Bolia
,
R. S.
,
Nelson
,
W. T.
,
Ericson
,
M. A.
, and
Simpson
,
B. D.
(
2000
). “
A speech corpus for multitalker communications research
,”
J. Acoust. Soc. Am.
107
,
1065
1066
.
10.
Bowen
,
A. L.
,
Ramachandran
,
R.
,
Muday
,
J. A.
, and
Schirillo
,
J. A.
(
2011
). “
Visual signals bias auditory targets in azimuth and depth
,”
Exp. Brain. Res.
214
,
403
414
.
11.
Bruijn
,
W. P. d.
, and
Boone
,
M. M.
(
2002
). “
Subjective experiments on the effects of combining spatialized audio and 2D video projection in audio-visual systems
,” in
Proceedings of the 112th Convention of the Audio Engineering Society
, paper no. 5582.
12.
Cavonius
,
C.
, and
Robbins
,
D.
(
1973
). “
Relationships between luminance and visual acuity in the rhesus monkey
,”
J. Physiol.
232
,
239
246
.
13.
Choe
,
C. S.
,
Welch
,
R. B.
,
Gilford
,
R. M.
, and
Juola
,
J. F.
(
1975
). “
The ‘ventriloquist effect’: Visual dominance or response bias?
,”
Percept. Psychophys.
18
,
55
60
.
14.
Ernst
,
M. O.
, and
Banks
,
M. S.
(
2002
). “
Humans integrate visual and haptic information in a statistically optimal fashion
,”
Nature
415
,
429
433
.
15.
Gardner
,
M. B.
(
1968
). “
Proximity image effect in sound localization
,”
J. Acoust. Soc. Am.
43
,
163
.
16.
Giard
,
M. H.
, and
Peronet
,
F.
(
1999
). “
Auditory-visual integration during multimodal object recognition in humans: A behavioral and electrophysiological study
,”
J. Cogn. Neurosci.
11
,
473
490
.
17.
Hairston
,
W.
,
Wallace
,
M.
,
Vaughan
,
J.
,
Stein
,
B.
,
Norris
,
J.
, and
Schirillo
,
J.
(
2003
). “
Visual localization ability influences cross-modal bias
,”
J. Cogn. Neurosci.
15
,
20
29
.
18.
Hládek
,
L.
,
Le Dantec
,
C. C.
,
Kopco
,
N.
, and
Seitz
,
A.
(
2013
). “
Ventriloquism effect and aftereffect in the distance dimension
,”
Proc. Meet. Acoust.
19
,
050042
.
19.
Ijsselsteijn
,
W.
,
Ridder
,
H. d.
,
Freeman
,
J.
,
Avons
,
S. E.
, and
Bouwhuis
,
D.
(
2001
). “
Determination of optimal data placement for psychometric function estimation: A computer simulation
,”
Presence-Teleop. Virt.
10
,
298
311
.
20.
ITU-R BS. 1284-1
(
2003
). “
General methods for the subjective assessment of sound quality
,” International Telecommunications Union.
21.
Jack
,
C. E.
, and
Thurlow
,
W. R.
(
1973
). “
Effects of degree of visual association and angle of displacement on the ‘ventriloquism’ effect
,”
Percept. Mot. Skills
37
,
967
979
.
22.
Jackson
,
C. V.
(
1953
). “
Visual factors in auditory localization
,”
Q. J. Exp. Psychol.
5
,
52
65
.
23.
Knudsen
,
E. I.
, and
Konishi
,
M.
(
1979
). “
Mechanisms of sound localization in the barn owl (Tyto alba)
,”
J. Comp. Physiol.
133
,
13
21
.
24.
Komiyama
,
S.
(
1989
). “
Subjective evaluation of angular displacement between picture and sound directions for HDTV sound systems
,”
J. Audio Eng. Soc.
37
,
210
214
.
25.
Lam
,
C. F.
,
Dubno
,
J. R.
, and
Mills
,
J. H.
(
1999
). “
Determination of optimal data placement for psychometric function estimation: A computer simulation
,”
J. Acoust. Soc. Am.
106
,
1969
1976
.
26.
Levitt
,
H.
(
1971
). “
Transformed up-down methods in psychoacoustics
,”
J. Acoust. Soc. Am.
49
,
467
477
.
27.
Lewald
,
J.
,
Ehrenstein
,
W.
, and
Guski
,
R.
(
2001
). “
Spatio-temporal constraints for auditory-visual integration
,”
Behav. Brain Res.
121
,
69
79
.
28.
Makous
,
J. C.
, and
Middlebrooks
,
J. C.
(
1990
). “
Two-dimensional sound localization by human listeners
,”
J. Acoust. Soc. Am.
87
,
2188
2200
.
29.
Mannerheim
,
P.
(
2011
). “Spatial
sound and stereoscopic vision
,” in
Proceedings of the 130th Convention of the Audio Engineering Society
, paper no. 8424.
30.
Martin
,
R. L.
,
McAnally
,
K. I.
,
Bolia
,
R. S.
,
Eberle
,
G.
, and
Brungart
,
D. S.
(
2012
). “
Spatial release from speech-on-speech masking in the median sagittal plane
,”
J. Acoust. Soc. Am.
131
,
378
385
.
31.
Melchior
,
F.
,
Brix
,
S.
,
Sporer
,
T.
,
Roder
,
T.
, and
Klehs
,
B.
(
2003
). “
Wave field synthesis in combination with 2D video projection
,” in
Proceedings of the 24th International Conference of the Audio Engineering Society
, paper no. 47.
32.
Melchior
,
F.
,
Fischer
,
J.
, and
Vries
,
D. d.
(
2006
). “
Audiovisual perception using Wave Field Synthesis in combination with augmented reality systems: Horizontal positioning
,” in
Proceedings of the 28th International Conference of the Audio Engineering Society
, paper no. 3–2.
33.
Mershon
,
D. H.
,
Desaulniers
,
D. H.
,
Amerson
,
T. L.
, and
Kiefer
,
S. A.
(
1980
). “
Visual capture in auditory distance perception: Proximity image effect reconsidered
,”
J. Aud. Res.
20
,
129
136
.
34.
Middlebrooks
,
J. C.
,
Makous
,
J.
, and
Green
,
D. M.
(
1989
). “
Directional sensitivity of sound-pressure levels in the human ear canal
,”
J. Acoust. Soc. Am.
86
,
89
108
.
35.
Pick
,
H. L.
,
Warren
,
D. H.
, and
Hay
,
J. C.
(
1969
). “
Sensory conflict in judgments of spatial direction
,”
Percept. Psychophys.
6
,
203
205
.
36.
Radeau
,
M.
(
1974
). “
Adaptation au déplacement prismatique sur la base d’une discordance entre la vision et l’audition” (“Adaptation prismatic displacement based on a discrepancy between vision and hearing”)
,
L’Année Psychologique
74
,
23
24
.
37.
Radeau
,
M.
, and
Bertelson
,
P.
(
1976
). “
The effect of a textured visual field on modality dominance in a ventriloquism situation
,”
Percept. Psychophys.
20
,
227
235
.
38.
Radeau
,
M.
, and
Bertelson
,
P.
(
1977
). “
Adaptation to auditory-visual discordance and ventriloquism in semirealistic situations
,”
Percept. Psychophys.
22
,
137
146
.
39.
Recanzone
,
G. H.
,
Makhamra
,
S. D.
, and
Guard
,
D. C.
(
1998
). “
Comparison of relative and absolute sound localization ability in humans
,”
J. Acoust. Soc. Am.
103
,
1085
1097
.
40.
Thurlow
,
W. R.
, and
Jack
,
C. E.
(
1973
). “
Certain determinants of the ‘ventriloquism effect,’ 
Percept. Mot. Skills
36
,
1171
1184
.
41.
Vatakis
,
A.
, and
Spence
,
C.
(
2007
). “
Crossmodal binding: Evaluating the unity assumption using audiovisual speech stimuli
,”
Percep. Psychophys.
69
,
744
756
.
42.
Wallace
,
M.
,
Roberson
,
G.
,
Hairston
,
W.
,
Stein
,
B.
,
Vaughan
,
J.
, and
Schirillo
,
J.
(
2004
). “
Unifying multisensory signals across time and space
,”
Exp. Brain. Res.
158
,
252
258
.
43.
Warren
,
D. H.
(
1979
). “
Spatial localization under conflict conditions: Is there a single explanation?
,”
Percept.
8
,
323
337
.
44.
Warren
,
D. H.
,
Welch
,
R. B.
, and
McCarthy
,
T. J.
(
1981
). “
The role of visual-auditory compellingness in the ventriloquism effect: Implications for transitivity among the spatial senses
,”
Percept. Psychophys.
30
,
557
564
.
45.
Weerts
,
T. C.
, and
Thurlow
,
W. R.
(
1971
). “
The effect of eye position and expectation on sound localization
,”
Percept. Psychophys.
9
,
35
39
.
46.
Welch
,
R. B.
(
1999
). “
Meaning, attention, and the ‘unity assumption’ in the intersensory bias of spatial and temporal perceptions
,”
Adv. Psychol.
129
,
371
387
.
47.
Welch
,
R. B.
, and
Warren
,
D. H.
(
1980
). “
Immediate perceptual response to intersensory discrepancy
,”
Psychol. Bull.
88
,
638
.
48.
Werner
,
S.
,
Liebetrau
,
J.
, and
Sporer
,
T.
(
2013
). “
Vertical sound source localization influenced by visual stimuli
,”
Signal Process. Res.
2
,
29
38
.
49.
Zahorik
,
P.
(
2003
). “
Auditory and visual distance perception: The proximity-image effect revisited
,”
J. Acoust. Soc. Am.
113
,
2270
2270
.
50.
Zchaluk
,
K.
, and
Foster
,
D. H.
(
2009
). “
Model-free estimation of the psychometric function
,”
Percept. Psychophys.
71
,
1414
1425
.
You do not currently have access to this content.