A behavioral response paradigm was used to measure hearing thresholds in bottlenose dolphins before and after exposure to 3 kHz tones with sound exposure levels (SELs) from 100 to 203 dB re 1μPa2s. Experiments were conducted in a relatively quiet pool with ambient noise levels below 55 dB re 1μPa2Hz at frequencies above 1 kHz. Experiments 1 and 2 featured 1-s exposures with hearing tested at 4.5 and 3 kHz, respectively. Experiment 3 featured 2-, 4-, and 8-s exposures with hearing tested at 4.5 kHz. For experiment 2, there were no significant differences between control and exposure sessions. For experiments 1 and 3, exposures with SEL=197dB re 1μPa2s and SEL195dB re 1μPa2s, respectively, resulted in significantly higher TTS4 than control sessions. For experiment 3 at SEL=195dB re 1μPa2s, the mean TTS4 was 2.8 dB. These data are consistent with prior studies of TTS in dolphins exposed to pure tones and octave band noise and suggest that a SEL of 195 dB re 1μPa2s is a reasonable threshold for the onset of TTS in dolphins and white whales exposed to midfrequency tones.

1.
American National Standards Institute
(ANSI) (
1994
). “
Acoustical terminology
,” ANSI S1.1-1994.
2.
Cornsweet
,
T. N.
(
1962
). “
The staircase method in psychophysics
,”
Am. J. Psychol.
75
,
485
491
.
3.
Dalecki
,
D.
,
Raeman
,
C. H.
,
Child
,
S. Z.
,
McAleavey
,
S. A.
and
Carstensen
,
E. L.
(
1999
). “
Lung response to low-frequency underwater sound
,”
J. Acoust. Soc. Am.
106
,
2165
(A).
4.
Egan
,
J. P.
,
Greenberg
,
G. Z.
, and
Schulman
,
A. I.
(
1961
). “
Operating characteristics, signal detectability, and the method of free response
,”
J. Acoust. Soc. Am.
33
,
993
1007
.
5.
Finneran
,
J. J.
(
2003
). “
An integrated computer-controlled system for marine mammal auditory testing
,” TD 3159,
SSC San Diego
, San Diego, CA.
6.
Finneran
,
J. J.
,
Dear
,
R.
,
Carder
,
D. A.
, and
Ridgway
,
S. H.
(
2003
). “
Auditory and behavioral responses of California sea lions (Zalophus californianus) to underwater impulses from an arc-gap transducer
,”
J. Acoust. Soc. Am.
114
,
1667
1677
.
7.
Finneran
,
J. J.
, and
Schlundt
,
C. E.
(
2004
). “
Effects of intense pure tones on the behavior of trained odontocetes
,” TR 1913,
SSC San Diego
, San Diego, CA.
8.
Finneran
,
J. J.
,
Schlundt
,
C. E.
,
Carder
,
D. A.
,
Clark
,
J. A.
,
Young
,
J. A.
,
Gaspin
,
J. B.
, and
Ridgway
,
S. H.
(
2000
). “
Auditory and behavioral responses of bottlenose dolphins (Tursiops truncatus) and a beluga whale (Delphinapterus leucas) to impulsive sounds resembling distant signatures of underwater explosions
,”
J. Acoust. Soc. Am.
108
,
417
431
.
9.
Finneran
,
J. J.
,
Schlundt
,
C. E.
,
Carder
,
D. A.
, and
Ridgway
,
S. H.
(
2002a
). “
Auditory filter shapes for the bottlenose dolphin (Tursiops truncatus) and the white whale (Delphinapterus leucas) derived with notched-noise
,”
J. Acoust. Soc. Am.
112
,
322
328
.
10.
Finneran
,
J. J.
,
Schlundt
,
C. E.
,
Dear
,
R.
,
Carder
,
D. A.
, and
Ridgway
,
S. H.
(
2002b
). “
Temporary shift in masked hearing thresholds (MTTS) in odontocetes after exposure to single underwater impulses from a seismic watergun
,”
J. Acoust. Soc. Am.
111
,
2929
2940
.
11.
GraphPad prism 4.0.2
,
GraphPad Software
, San Diego, CA.
12.
Green
,
D. M.
,
DeFerrari
,
H. A.
,
McFadden
,
D.
,
Pearse
,
J. S.
,
Popper
,
A. N.
,
Richardson
,
W. J.
,
Ridgway
,
S. H.
, and
Tyack
,
P. L.
(
1994
).
Low Frequency Sound and Marine Mammals: Current Knowledge and Research Needs
(
National Academy Press
, Washington, DC).
13.
Hirsh
,
I. J.
, and
Bilger
,
R. C.
(
1955
). “
Auditory-threshold recovery after exposure to pure tones
,”
J. Acoust. Soc. Am.
27
,
1186
1194
.
14.
Hirsh
,
I. J.
, and
Ward
,
W. D.
(
1952
). “
Recovery of the auditory threshold after strong acoustic stimulation
,”
J. Acoust. Soc. Am.
24
,
131
141
.
15.
Humes
,
L. E.
(
1980
). “
Temporary threshold shift for masked pure tones
,”
Audiology
19
,
335
345
.
16.
Jepson
,
P. D.
,
Arbelo
,
M.
,
Deaville
,
R.
,
Patterson
,
I. A.R.
,
Castro
,
P.
,
Baker
,
J. R.
,
Degollada
,
E.
,
Ross
,
H. M.
,
Herráez
,
P.
,
Pocknell
,
A. M.
,
Rodriguez
,
E.
,
Howie
,
F. E.
,
Espinosa
,
A.
,
Reid
,
R. J.
,
Jaber
,
J. R.
,
Martin
,
V.
,
Cunningham
,
A. A.
, and
Fernandez
,
A.
(
2003
). “
Gas-bubble lesions in stranded cetaceans
,”
Nature (London)
425
,
575
576
.
17.
Johnson
,
C. S.
(
1967
). “
Sound detection thresholds in marine mammals
,” in
Marine Bioacoustics
, edited by
W. N.
Tavolga
(
Pergamon
, Oxford), pp.
247
260
.
18.
Kastak
,
D.
, and
Schusterman
,
R. J.
(
1996
). “
Temporary threshold shift in a harbor seal (Phoca vitulina)
,”
J. Acoust. Soc. Am.
100
,
1905
1908
.
19.
Kastak
,
D.
,
Schusterman
,
R. J.
,
Southall
,
B. L.
, and
Reichmuth
,
C. J.
(
1999
). “
Underwater temporary threshold shift induced by octave-band noise in three species of pinniped
,”
J. Acoust. Soc. Am.
106
,
1142
1148
.
20.
Marshall
,
W. J.
(
1996
). “
Descriptors of impulse signal levels commonly used in underwater acoustics
,”
IEEE J. Ocean. Eng.
21
,
108
110
.
21.
Mills
,
J. H.
,
Osgithorpe
,
J. D.
,
Burdick
,
C. K.
,
Patterson
,
J. H.
, and
Mozo
,
B.
(
1983
). “
Temporary threshold shifts produced by exposure to low-frequency noises
,”
J. Acoust. Soc. Am.
73
,
918
923
.
22.
Moore
,
P. W.B.
,
Finneran
,
J. J.
, and
Houser
,
D. S.
(
2004
). “
Hearing loss and echolocation signal change in dolphins
,”
J. Acoust. Soc. Am.
116
,
2503
(A).
23.
Nachtigall
,
P. E.
,
Pawloski
,
J.
, and
Au
,
W. W.L.
(
2003
). “
Temporary threshold shifts and recovery following noise exposure in the Atlantic bottlenosed dolphin (Tursiops truncatus)
,”
J. Acoust. Soc. Am.
113
(
6
),
3425
3429
.
24.
Nachtigall
,
P. E.
,
Supin
,
A.
,
Pawloski
,
J.
, and
Au
,
W. W.L.
(
2004
). “
Temporary threshold shifts after noise exposure in the bottlenose dolphin (Tursiops truncatus) measured using evoked auditory potentials
,”
Marine Mammal Sci.
20
,
673
687
.
25.
National Institute for Occupational Safety and Health
(NIOSH) (
1998
). “
Criteria for a recommended standard: Occupational noise exposure, revised criteria 1998
,” Publication No. 98-126, Cincinnati, OH.
26.
Parker
,
D. E.
,
Tubbs
,
R. L.
,
Johnston
,
P. A.
, and
Johnston
,
L. S.
(
1976
). “
Influence of auditory fatigue on masked pure-tone thresholds
,”
J. Acoust. Soc. Am.
60
,
881
885
.
27.
Ridgway
,
S. H.
, and
Carder
,
D. A.
(
1997
). “
Hearing deficits measured in some Tursiops truncatus, and discovery of a deaf/mute dolphin
,”
J. Acoust. Soc. Am.
101
,
590
594
.
28.
Schlundt
,
C. E.
,
Finneran
,
J. J.
,
Carder
,
D. A.
, and
Ridgway
,
S. H.
(
2000
). “
Temporary shift in masked hearing thresholds of bottlenose dolphins, Tursiops truncatus, and white whales, Delphinapterus leucas, after exposure to intense tones
,”
J. Acoust. Soc. Am.
107
,
3496
3508
.
29.
U.S. Department of Commerce and U.S. Department of the Navy
(
2001
). “
Joint interim report Bahamas marine mammal stranding event of 14-16 March 2000
,” Department of Commerce, Washington, DC.
30.
Ward
,
W. D.
,
Glorig
,
A.
, and
Sklar
,
D. L.
(
1958
). “
Dependency of temporary threshold shift at 4 kc on intensity and time
,”
J. Acoust. Soc. Am.
30
,
944
954
.
31.
Ward
,
W. D.
,
Glorig
,
A.
, and
Sklar
,
D. L.
(
1959
). “
Temporary threshold shift from octave-band noise: applications to damage-risk criteria
,”
J. Acoust. Soc. Am.
31
,
522
528
.
32.
Yelverton
,
J. T.
,
Richmond
,
D. R.
,
Fletcher
,
E. R.
, and
Jones
,
R. K.
(
1973
). “
Safe distances from underwater explosions for mammals and birds
,” DNA 3114T,
Lovelace Foundation for Medical Education and Research
, Albuquerque, New Mexico.
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