Dolphins are hypothesized to deduce the swimming direction of group members by attending to the spectral pattern of whistle harmonics. This is known as the direction of movement cue hypothesis and may facilitate coordination of complex group behavior when visibility is poor. The direction of movement cue hypothesis hinges on the assumption that dolphins can discriminate between whistles with different harmonic patterns that are associated with signaler orientation. This assumption was tested with a bottlenose dolphin. Whistles were recorded from a dolphin at different azimuth positions (0° to 180° in 45° increments). Noise-free, synthetic whistles were created to mimic the direction-dependant spectral profiles of the recorded whistles. A dolphin was then tested in its ability to discriminate between the synthetic whistles using fixed level and roving level conditions. The dolphin's discrimination performance in both the fixed and roving level conditions was near 100% for whistles separated by angles greater than 45°, and near chance for 45° separations. Computer simulations of the task, along with the dolphin's performance, suggest that the dolphin's discrimination was level invariant and based on the spectral pattern of the whistles.
REFERENCES
1.
Au
, W. W. L.
(1992
). “Target sonar discrimination cues
,” in Marine Mammal Sensory Systems
, edited by J. A.
Thomas
, R. A.
Kastelein
, and A. Y.
Supin
(Plenum Press
, New York
), pp. 357
–376
.2.
Au
, W. W. L.
(1993
). The Sonar of Dolphins
(Springer
, New York
), pp. 1
–277
.3.
Au
, W. W. L.
, Andersen
, L. N.
, Rasmussen
, A. R.
, Roitblat
, H. L.
, and Nachtigall
, P. E.
(1995
). “Neural network modeling of a dolphin's sonar discrimination capabilities
,” J. Acoust. Soc. Am.
98
, 43
–50
.4.
Au
, W. W. L.
, Branstetter
, B. K.
, Benoit-Bird
, K. J.
, and Kastelein
, R. A.
(2009
). “Acoustic basis for fish prey discrimination by echolocating dolphins and porpoises
,” J. Acoust. Soc. Am.
126
, 460
–467
.5.
Au
, W. W. L.
, and Moore
, P. W. B.
(1990
). “Critical ratio and critical bandwidth for the Atlantic bottlenose dolphin
,” J. Acoust. Soc. Am.
88
, 1635
–1638
.6.
Benoit-Bird
, K. J.
, and Au
, W. W. L.
(2009
). “Phonation behavior of cooperatively foraging spinner dolphins
,” J. Acoust. Soc. Am.
125
, 539
–546
.7.
Berg
, B. G.
(1996
). “On the relationship between comodulation masking release and temporal modulation transfer functions
,” J. Acoust. Soc. Am.
100
, 1013
–1023
.8.
Blomqvist
, C.
, and Amundin
, M.
(2004
). “High-frequency burst-pulse sounds in agonistic/aggressive interactions in bottlenose dolphins, Tursiops truncatus
,” in Echolocation in Bats and Dolphins
, edited by J. A.
Thomas
, C. F.
Moss
, and M.
Vater
(University of Chicago Press
, Chicago, IL
), pp. 425
–431
.9.
Branstetter
, B. K.
, and Finneran
, J. J.
(2008
). “Comodulation masking release in bottlenose dolphins (Tursiops truncatus)
,” J. Acoust. Soc. Am.
124
, 625
–633
.10.
Branstetter
, B. K.
, Mercado
, E.
, III, and Au
, W. W. L.
(2007
). “Representing multiple discrimination cues in a computational model of the bottlenose dolphin auditory system
,” J. Acoust. Soc. Am.
122
, 2459
–2468
.11.
Branstetter
, B. K.
, Moore
, P. W.
, Finneran
, J. J.
, Tormey
, M. N.
, and Aihara
, H.
(2012
). “Directional properties of bottlenose dolphin (Tursiops truncatus) clicks, burst-pulse, and whistle sounds
,” J. Acoust. Soc. Am.
131
, 1613
–1621
.12.
Caldwell
, M. C.
, Caldwell
, D. K.
, and Tyack
, T. L.
(1990
). “Review of the signature-whistle hypothesis for the Atlantic Bottlenose Dolphin
,” in The Bottlenose Dolphin
, edited by S.
Leatherwood
and R. R.
Reeves
(Academic Press, Inc.
, San Diego, CA
), pp. 199
–234
.13.
Conner
, R. C.
(2000
). “Group living in whales and dolphins
,” in Cetacean Societies: Field Studies of Dolphins and Whales
, edited by J.
Mann
, R. C.
Conner
, P. L.
Tyack
, and H.
Whitehead
(University of Chicago Press
, Chicago, IL
), pp. 199
–218
.14.
Dooling
, R. J.
, and Okanoya
, K.
(1995
). “Psychophysical methods for assessing perceptual categories
,” in Methods in Comparative Psychoacoustics
, edited by G. M.
Klump
, R. J.
Dooling
, R. R.
Fay
, and W. C.
Stebbins
(Birkhäuser Verlag
, Basel, Switzerland
), pp. 307
–318
.15.
Evans
, W. E.
(1973
). “Echolocation by marine delphinids and one species of freshwater dolphin
,” J. Acoust. Soc. Am.
54
, 191
–199
.16.
Evans
, W. E.
, and Prescott
, J. H.
(1962
). “Observations of the sound production capabilities of the Bottlenose Porpoise: A study of whistles and clicks
,” Zoologica
47
, 121
–128
.17.
Finneran
, J. J.
, and Schlundt
, C. E.
(2011
). “Subjective loudness level measurements and equal loudness contours in a bottlenose dolphin (Tursiops truncatus)
,” J. Acoust. Soc. Am.
130
, 3124
–3136
.18.
Finneran
, J. J.
, Schlundt
, C. E.
, Carder
, D. A.
, and Ridgway
, S. H.
(2002
). “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
.19.
Gellerman
, L. W.
(1933
). “Chance orders of alternating stimuli in visual discrimination experiments
,” J. Genetic Psychol.
42
, 206
–208
.20.
Gillman
, B.
(Ed). (2000
). “Perceptual constancies
,” in Encyclopedia of Psychology
, edited by A. E.
Kazdin
(American Psychological Association
, Washington, DC
), pp. 89
–93
.21.
Harley
, H. E.
, and DeLong
, C. M.
(2008
). “Echoic object recognition by the bottlenose dolphin
,” Comparative Cogn. Behav. Rev.
3
, 46
–65
.22.
Herman
, L. M.
, Richards
, D. G.
, and Wolz
, J. P.
(1984
). “Comprehension of sentences by bottlenosed dolphins
,” Cognition
16
, 129
–219
.23.
Hernandez
, E. N.
, Solangi
, M.
, and Kuczaj
, S. A.
, II (2010
). “Time and frequency parameters of bottlenose dolphin whistles as predictors of surface behavior in the Mississippi Sound
,” J. Acoust. Soc. Am.
127
, 3232
–3238
.24.
Houser
, D. S.
, and Finneran
, J. J.
(2006
). “Variation in the hearing sensitivity of a dolphin population obtained through the use of evoked potential audiometry
,” J. Acoust. Soc. Am.
120
, 4090
–4099
.25.
Janik
, V. M.
(2000a
). “Food-related bray calls in wild bottlenose dolphins (Tursiops truncatus)
,” Proc. R. Soc. London Ser. B
267
, 923
–927
.26.
Janik
, V. M.
(2000b
). “Source levels and the estimated active space of bottlenose dolphin (Tursiops truncatus) whistles in the Moray Firth, Scotland
,” J. Comp. Physiol. A
186
, 673
–680
.27.
Janik
, V. M.
(2000c
). “Whistle matching in wild bottlenose dolphins (Tursiops truncatus)
,” Science
289
, 1355
–1357
.28.
Janik
, V. M.
, Dehnhardt
, G.
, and Todt
, D.
(1994
). “Signature whistle variations in a bottlenosed dolphin, Tursiops truncatus
,” Behav. Ecol. Sociobiol.
35
, 243
–248
.29.
Janik
, V. M.
, Sayigh
, L. S.
, and Wells
, R. S.
(2006
). “Signature whistle shape conveys identity information to bottlenose dolphins
,” Proc. Natl. Acad. Sci. U.S.A.
103
, 8293
–8297
.30.
Janik
, V. M.
, and Slater
, P. J. B.
(1998
). “Context-specific use suggests that bottlenose dolphin signature whistles are cohesion calls
,” Anim. Behav.
56
, 829
–838
.31.
Johnson
, C. S.
(1968a
). “Relation between absolute threshold and duration-of-tone pulses in the bottlenosed porpoise
,” J. Acoust. Soc. Am.
43
, 757
–763
.32.
Johnson
, C. S.
(1968b
). “Sound detection thresholds in marine mammals
,” Mar. Bioacoust.
2
, 247
–260
.33.
Kidd
, G. J.
, Uchanski
, R. M.
, Mason
, C. R.
, and Deliwala
, P. S.
(1993
). “Discriminability of narrow-band sounds in the absence of level cues
,” J. Acoust. Soc. Am.
93
, 1028
–1037
.34.
Lammers
, M. O.
, and Au
, W. W. L.
(2003
). “Directionality in the whistles of Hawaiian spinner dolphins (Stenella longirostris): A signal feature to cue direction of movement?
,” Mar. Mammal Sci.
19
, 249
–264
.35.
Lammers
, M. O.
, Au
, W. W. L.
, and Herzing
, D. L.
(2003
). “The broadband social acoustic signaling behavior of spinner and spotted dolphins
,” J. Acoust. Soc. Am.
114
, 1629
–1639
.36.
Lemonds
, D. W.
(1999
). “Auditory filter shapes in an Atlantic bottlenose dolphin (Tursiops truncatus)
,” in Psychology
(University of Hawaii
, Manoa
), p. 74
.37.
Lilly
, J. C.
, and Miller
, A. M.
(1961
). “Sounds emitted by the bottlenose dolphin
,” Science
133
, 1689
–1693
.38.
May-Collado
, L. J.
, and Wartzok
, D.
(2009
). “A characterization of Guyana dolphin (Sotalia guianensis) whistles from Costa Rica: The importance of broadband recording systems
,” J. Acoust. Soc. Am.
125
, 1202
–1213
.39.
Miller
, P. J. O.
(2002
). “Mixed-directionality of killer whale stereotyped calls: A direction of movement cue?
,” Behav. Ecol. Sociobiol.
52
, 262
–270
.40.
Mulsow
, J.
, and Finneran
, J. J.
(2011
). “New approaches for studying the perception of vocal signals in otariid pinnipeds
,” J. Acoust. Soc. Am.
129
, 2504
.41.
Overstrom
, N. A.
(1983
). “Association between burst-pulse sounds and aggressive behavior in captive Atlantic bottlenosed dolphins (Tursiops truncatus)
,” Zoo Biol.
2
, 93
–103
.42.
Pack
, A. A.
, Herman
, L. M.
, Hoffmann-Kuhnt
, M.
, and Branstetter
, B. K.
(2002
). “The object behind the echo: Dolphins (Tursiops truncatus) perceive object shape globally through echolocation
,” Behav. Process.
58
, 1
–26
.43.
Pols
, L. C. W.
(1997
). “Flexible, robust, and efficient human speech recognition
,” Proc. Inst. Phonetic Sci.
21
, 1
–10
.44.
Quintana-Rizzo
, E.
, Mann
, D. A.
, and Wells
, R. S.
(2006
). “Estimated communication range of social sounds used by bottlenose dolphins (Tursiops truncatus)
,” J. Acoust. Soc. Am.
120
, 1671
–1683
.45.
R Development Core Team (
2012
). “A language and environment for statistical computing,” (R Foundation for Statistical Computing, Vienna, Austria).46.
Ralston
, J. V.
, and Herman
, L. M.
(1995
). “Perception and generalization of frequency contours by a bottlenose dolphin (Tursiops truncatus)
,” J. Comparative Psychol.
109
, 268
–277
.47.
Regan
, M. P.
(1994
). “Linear half-wave rectification of modulated sinusoids
,” Appl. Math. Comput.
62
, 61
–79
.48.
Richards
, D. G.
, Wolz
, J. P.
, and Herman
, L. M.
(1984
). “Vocal mimicry of computer-generated sounds and vocal labeling of objects by the bottlenosed dolphin, Tursiops truncatus
,” J. Comparative Psychol.
98
, 10
–28
.49.
Ridgway
, S. H.
, Carder
, D. A.
, and Romano
, T. A.
(1991
). “The victory squeal of dolphins and white whales on the surface and at 100 m or more in depth (A)
,” J. Acoust. Soc. Am.
90
, 2335
.50.
Roitblat
, H. L.
, Ketten
, D.
, Au
, W. W. L.
, and Nachtigall
, P. E.
(1996
). “A computational model of early stages of dolphin hearing (A)
,” J. Acoust. Soc. Am.
100
, 2643
.51.
Slaney
, M.
(1993
). “An efficient implementation of the Patterson-Holdsworth filter bank
,” Apple Comput. Tech. Rep. No. 35 (Apple Computer Library, Cupertino, CA).52.
Smolker
, R. A.
, Mann
, J.
, and Smuts
, B. B.
(1993
). “Use of signature whistles during separations and reunions by wild bottlenose dolphin mothers and infants
,” Behav. Ecol. Sociobiol.
33
, 393
–402
.53.
Thompson
, R. K. R.
, and Herman
, L. M.
(1975
). “Underwater frequency discrimination in the bottlenosed dolphin (1–140 kHz) and the human (1–8 kHz)
,” J. Acoust. Soc. Am.
57
, 943
–948
.54.
Trickey
, J. S.
, Branstetter
, B. B.
, and Finneran
, J. J.
(2011
). “Auditory masking with environmental, comodulated, and Gaussian noise in bottlenose dolphins (Tursiops truncatus)
,” J. Acoust. Soc. Am.
128
, 3799
–3804
.55.
Tyack
, P. L.
(1997
). “Development and social functions of signature whistles in bottlenose dolphins Tursiops truncatus
,” Bioacoustics
8
, 21
–46
.56.
Viemeister
, N. F.
(1979
). “Temporal modulation transfer functions based upon modulation thresholds
,” J. Acoust. Soc. Am.
66
, 1364
–1380
.57.
Yuen
, M. M. L.
, Nachtigall
, P. E.
, Breese
, M.
, and Vlachos
, S. A.
(2007
). “The perception of complex tones by a false killer whale (Pseudorca crassidens)
,” J. Acoust. Soc. Am.
121
, 1768
–1774
.© 2013 Acoustical Society of America.
2013
Acoustical Society of America
You do not currently have access to this content.