Echolocating dolphins emit trains of clicks and receive echoes from ocean targets. They often emit each successive ranging click about 20 ms after arrival of the target echo. In echolocation, decisions must be made about the target—fish or fowl, predator or food. In the first test of dolphin auditory decision speed, three bottlenose dolphins (Tursiops truncatus) chose whistle or pulse burst responses to different auditory stimuli randomly presented without warning in rapid succession under computer control. The animals were trained to hold pressure catheters in the nasal cavity so that pressure increases required for sound production could be used to split response time (RT) into neural time and movement time. Mean RT in the youngest and fastest dolphin ranged from 175 to 213 ms when responding to tones and from 213 to 275 ms responding to pulse trains. The fastest neural times and movement times were around 60 ms. The results suggest that echolocating dolphins tune to a rhythm so that succeeding pulses in a train are produced about 20 ms over target round-trip travel time. The dolphin nervous system has evolved for rapid processing of acoustic stimuli to accommodate for the more rapid sound speed in water compared to air.

1.
Amundin
,
M.
, and
Andersen
,
S. H.
(
1983
). “
Bony nares air pressure and nasal plug muscle activity during click production in the Harbor porpoise, Phocoena phocoena and the bottlenosed dolphin, Tursiops truncatus
,”
J. Exp. Biol.
105
,
275
282
.
2.
Au
,
W. W. L.
,
Floyd
,
R. W.
,
Penner
,
R. H.
, and
Murchison
,
A. E.
(
1974
). “
Measurement of echolocation signals of the Atlantic bottlenose dolphin, Tursiops truncatus Montagu, in open waters
,”
J. Acoust. Soc. Am.
56
,
1280
1290
.
3.
Backus
,
R. H.
, and
Schevill
,
W. E.
(
1966
). “
Physeter clicks
,” in
Whales, Dolphins, and Porpoises
, edited by
K. S.
Norris
(
University of California Press
,
Berkeley, CA
), pp.
510
528
.
4.
Blackwood
,
D.
(
2003
). “
Vocal response times to acoustic stimuli in white whales and bottlenose dolphins
,” Ph.D. dissertation, Wildlife and Fisheries Sciences,
Texas A&M University
, College Station, TX, pp.
1
144
.
5.
Bullock
,
T. H.
, and
Ridgway
,
S. H.
(
1972
). “
Evoked potentials in the central auditory system of alert porpoises to their own and artificial sounds
,”
J. Neurobiol.
3
,
79
99
.
36.
Caldwell
,
M. C.
, and
Caldwell
,
D. K.
(
1968
). “
Vocalization of naive captive dolphins in small groups
,”
Science
,
159
,
1121
1123
.
37.
Cranford
,
T. W.
,
Amundin
,
M.
, and
Norris
,
K. S.
(
1996
). “
Functional morphology and homology in the odontocete nasal complex: Implications for sound generation
,”
J. Morphol.
228
,
223
285
.
6.
Davis
,
M.
,
Gendelman
,
D. S.
,
Tischler
,
M. D.
, and
Gendelman
,
P. M.
(
1982
). “
A primary acoustic startle circuit: Lesion and stimulation studies
,”
J. Neurosci.
2
,
791
805
.
7.
Dawson
,
W. W.
,
Hawthorne
,
M.
,
Jenkins
,
R.
, and
Goldston
,
R.
(
1982
). “
Giant neural systems of the inner retina and optic nerve of small whales
,”
J. Comp. Neurol.
205
,
1
7
.
8.
De Graaf
,
A. S.
(
1967
).
Anatomical Aspects of the Cetacean Brain Stem
(
Von Gorcum
,
Assen, The Netherlands
), pp.
1
169
.
9.
Demski
,
L. S.
,
Ridgway
,
S. H.
, and Schwanzel–
Fukuda
,
M.
(
1990
). “
The terminal nerve of dolphins: Gross structure, histology, and luteinizing-hormone-releasing hormone immunocytochemistry
,”
Brain Behav. Evol.
36
,
249
261
.
10.
Dormer
,
K.
(
1979
). “
Mechanism of sound production and air recycling in delphinids: Cineradiographic evidence
,”
J. Acoust. Soc. Am.
65
,
229
239
.
11.
Ferrand
,
C.
,
Blood
,
G. H.
, and
Gilbert
,
H. R.
(
1991
). “
A continuous flow model for phonatory reaction time
,”
J. Speech Hear. Res.
14
,
517
525
.
14.
Ghose
,
K.
, and
Moss
,
C. F.
(
2006
). “
Steering by hearing: A bat’s acoustic gaze is linked to its flight motor output by a delayed, adaptive linear law
,”
J. Neurosci.
26
,
1704
1710
.
15.
Gillam
,
E. H.
,
Ulanovsky
,
N.
, and
McCracken
,
G. F.
(
2007
). “
Rapid jamming avoidance in biosonar
,”
Proc. R. Soc. London, Ser. B.
274
,
651
660
.
12.
Greenwald
,
A. G.
, and
Shulman
,
H. G.
(
1973
). “
On doing two things at once: Elimination of the psychological refractory period effect
,”
J. Exp. Psychol.
101
,
70
76
.
13.
Grell
,
A.
,
Sundberg
,
J.
,
Ternström
,
S.
,
Plok
,
M.
, and
Altenmuüller
,
E.
(
2009
). “
Rapid pitch correction in choir singers
,”
J. Acoust. Soc. Am.
126
,
407
413
.
38.
Hillyard
,
S. A.
, and
Kutas
,
M.
(
1983
). “
Electrophysiology of cognitive processing
,”
Annu. Rev. Psychol.
34
,
33
61
.
16.
Houser
,
D. S.
,
Finneran
,
J.
Carder
,
D.
,
Van Bonn
,
W.
,
Smith
,
C.
,
Hoh
,
C.
,
Mattrey
,
R.
, and
Ridgway
,
S.
(
2004
). “
Structural and functional imaging of bottlenose dolphin (Tursiops truncatus) cranial anatomy
,”
J. Exp. Biol.
207
,
3657
3665
.
17.
Houser
,
D. S.
,
Finneran
,
J. J.
, and
Ridgway
,
S. H.
(
2010
). “
Research with navy marine mammals benefits animal care, conservation and biology
,”
Int. J. Comp. Psychol.
23
,
249
268
.
18.
Jen
P. H. -S.H.-S.
(
1982
).
Electrophysiological Analysis of Echolocation System in Bats. Contributions to Sensory Physiology
, vol.
6
(
Academic Press
,
New York, NY
), pp.
115
158
.
19.
Kadane
,
J.
, and
R. H.
Penner
. (
1983
). “
Range ambiguity and pulse interval jitter in the bottlenose dolphin
,”
J. Acoust. Soc. Am.
74
,
1059
1062
.
20.
Mackay
,
R. S.
, and
Liaw
,
H. M.
(
1981
). “
Dolphin vocalization mechanisms
,”
Science
212
,
675
678
.
21.
Masters
,
W. M.
,
Moffat
,
A. J. M.
, and
Simmons
,
J. R.
(
1985
). “
Sonar tracking of horizontally moving targets by the big brown bat, Eptesicus fuscus
,”
Science
228
,
1331
1333
.
24.
Meyer
,
D. E.
,
Osman
,
A. M.
,
Irwin
,
D. E.
, and
Yantis
,
S.
(
1988
). ‘
Modern mental chronometry
,”
Biol. Psychol.
26
,
3
67
.
23.
Morozov
,
V. P.
,
Akopian
,
A. I.
,
Burdin
,
V. I.
,
Zaytseva
,
K. A.
,
Sokovykh
,
Y. A.
(
1972
). “
Repetition rate of ranging signals of dolphins as a function of distance to target
,”
Biofizika
17
,
139
144
.
22.
Murchison
,
A. E.
(
1980
). “
Detection range and range resolution of echolocating bottlenose porpoise (Tursiops truncatus)
” in
Animal Sonar Systems
, edited by
R. G.
Busnel
and
J. F.
Fish
(
Plenum Press
,
New York, NY
), pp.
43
70
.
39.
Oelschläger
,
H. A.
,
Haas-Rioth
,
M.
,
Fung
,
C.
,
Ridgway
,
S. H.
, and
Knauth
,
M.
(
2008
). “
Morphology and Evolutionary Biology of the Dolphin (Delphinus sp.) Brain-MR Imaging and Conventional Histology
,”
Brain Behav. Evol.
71
,
68
86
.
25.
Penner
,
R. H.
(
1988
). “
Attention and detection in dolphin echolocation
,” in
Animal Sonar: Processes and Performance
, edited by
P. E.
Nachtigall
and
P. W. B.
Moore
(
Plenum Press
,
New York, NY
), pp.
707
713
.
26.
Posner
,
M. I.
(
2005
). “
Timing the brain: Mental chronometry as a tool in neuroscience
,”
PLoS Biol.
3
(
2
),
e51
.
27.
Richman
,
B.
(
1978
). “
The synchronization of voices by Gelada monkeys
,”
Primates
19
,
569
581
.
29.
Ridgway
,
S. H.
,
Bullock
,
T. H.
,
Carder
,
D. A.
,
Seeley
,
R. L.
,
Woods
,
D.
, and
Galambos
,
R.
(
1981
). “
Auditory brainstem response in dolphins
,”
Proc. Natl. Acad. Sci. U.S.A.
78
,
943
1947
.
30.
Ridgway
,
S. H.
, and
Carder
,
D. A.
(
1988
). “
Nasal pressure and sound production in an echolocating white whale, Delphinapterus leucas
,” in
Animal Sonar: Processes and Performance
, edited by
P. E.
Nachtigall
and
P. W. B.
Moore
(
Plenum Press
,
New York, NY
), pp.
53
60
.
28.
Ridgway
,
S. H.
,
Carder
,
D. A.
,
Green
,
R. F.
,
Gaunt
,
A. S.
,
Gaunt
,
S. L. L.
, and
Evans
,
W. E.
(
1978
). “
Electromyographic and pressure events in the nasolaryngeal system of dolphins during sound production
,” in
Animal Sonar Systems
, edited by
R. G.
Busnel
and
J. F.
Fish
(
Plenum
,
New York, NY
), pp.
239
249
.
40.
Ridgway
,
S. H.
,
Carder
,
D. A.
,
Kamolnick
,
P. L.
,
Skaar
,
D. J.
, and
Root
,
W. A.
(
1991
). “
Acoustic response times (RTs) for Tursiops truncatus
,”
J. Acoust. Soc. Am.
89
,
1967
1968
.
31.
Ridgway
,
S. H.
,
Demski
,
L. S.
,
Bullock
,
T. H.
, and
Schwanzel–Fukuda
,
M.
(
1987
). “
The terminal nerve in odontocete cetaceans
,” in
The Terminal Nerve (Nervus Terminalis): Structure, Function and Evolution
, edited by
L.
Demski
and
M.
Schwanzel–Fukuda
. Ann. N. Y. Acad. Sci. 519,
201
212
.
41.
Ridgway
,
S. H.
,
Houser
,
D.
,
Finneran
,
J. J.
,
Carder
,
D. A.
,
Keogh
,
M.
,
Van Bonn
,
W.
,
Smith
,
C. R.
,
Scadeng
,
M.
,
Mattrey
,
R.
, and
Hoh
,
C.
(
2006
). “
Functional Imaging of Dolphin Brain Metabolism and Blood Flow
,”
J. Exp. Biol.
209
,
2902
2910
.
42.
Ridgway
,
S. H.
,
Keogh
,
M.
,
Carder
,
D. A.
,
Finneran
,
J. J.
,
Kamolnick
,
T.
,
Todd
,
M.
, and
Goldblatt
,
A.
(
2009
). “
Dolphins maintain cognitive performance during 72 to 120 hours of continuousauditory vigilance
,”
J. Exp. Biol.
212
,
1519
1527
.
34.
Saslow
,
C. A.
(
1972
). “
Behavioral definition of minimal reaction time in monkeys
,”
J. Exp. Anal. Behav.
18
,
87
106
.
32.
Supin
,
A. Y.
,
Mukhametov
,
L. M.
,
Ladygina
,
T. F.
,
Popov
,
V. V.
,
Mass
,
A. M.
, and
Poliakova
,
E. G.
(
1978
).
Electrophysiological Study of the Dolphin Brain
(In Russian) (
Nauk
,
Moscow, Russia
), pp.
1
213
.
33.
Surlykke
,
A.
,
Ghose
, K.
, and
Moss
,
C. F.
(
2009
). “
Acoustic scanning of natural scenes by echolocation in the big brown bat, Eptesicus fuscus
,”
J. Exp. Biol.
212
,
1011
1020
.
35.
Woods
,
D. L.
,
Ridgway
,
S. H.
,
Carder
,
D. A.
, and
Bullock
,
T.H.
(
1986
). “
Middle- and long-latency auditory event-related potentials in dolphins
,” in
Dolphin Cognition and Behavior: A Comparative Approach
, edited by
R.
Schusterman
,
J.
Thomas
, and
F.
Wood
(
Lawrence Erlbaum Associates
,
Hillsdale, NJ
), pp.
61
77
.
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