The neural representation of the dolphin broadband biosonar click was investigated by measuring auditory brainstem responses (ABRs) to “self-heard” clicks masked with noise bursts having various high-pass cutoff frequencies. Narrowband ABRs were obtained by sequentially subtracting responses obtained with noise having lower high-pass cutoff frequencies from those obtained with noise having higher cutoff frequencies. For comparison to the biosonar data, ABRs were also measured in a passive listening experiment, where external clicks and masking noise were presented to the dolphins and narrowband ABRs were again derived using the subtractive high-pass noise technique. The results showed little change in the peak latencies of the ABR to the self-heard click from 28 to 113 kHz; i.e., the high-frequency neural responses to the self-heard click were delayed relative to those of an external, spectrally “pink” click. The neural representation of the self-heard click is thus highly synchronous across the echolocation frequencies and does not strongly resemble that of a frequency modulated downsweep (i.e., decreasing-frequency chirp). Longer ABR latencies at higher frequencies are hypothesized to arise from spectral differences between self-heard clicks and external clicks, forward masking from previously emitted biosonar clicks, or neural inhibition accompanying the emission of clicks.
References
1.
Au
, W. W. L.
(1993
). The Sonar of Dolphins
(Springer-Verlag
, New York
), 227
pp.2.
Au
, W. W. L.
, and Martin
, S. W.
(2012
). “Why dolphin biosonar performs so well in spite of mediocre ‘equipment,’
” IET Radar, Sonar Navig.
6
, 566
−575
.3.
Au
, W. W. L.
, and Simmons
, J. A.
(2007
). “Echolocation in dolphins and bats
,” Phys. Today
60
(9
), 40
−45
.4.
Borg
, E.
, and Zakrisson
, J. E.
(1975
). “The activity of the stapedius muscle in man during vocalization
,” Acta Otolaryngol.
79
, 325
–333
.5.
Burkard
, R.
(1984
). “Sound pressure level measurement and spectral analysis of brief acoustic transients
,” Electroencephalogr. Clin. Neurophysiol.
57
, 83
–91
.6.
Burkard
, R.
, and Hecox
, K. E.
(1987
). “The effect of broadband noise on the human brain-stem auditory evoked response. IV. Additivity of forward-masking and rate-induced wave V latency shifts
,” J. Acoust. Soc. Am.
81
, 1064
–1072
.7.
Burkard
, R.
, and Moss
, C. F.
(1994
). “The brain-stem auditory-evoked response in the big brown bat (Eptesicus fuscus) to clicks and frequency-modulated sweeps
,” J. Acoust. Soc. Am.
96
, 801
–810
.8.
Don
, M.
, and Eggermont
, J. J.
(1978
). “Analysis of the click-evoked brainstem potentials in man using high-pass noise masking
,” J. Acoust. Soc. Am.
63
, 1084
–1092
.9.
Eggermont
, J. J.
(1979
). “Narrow-band AP latencies in normal and recruiting human ears
,” J. Acoust. Soc. Am.
65
, 463
–470
.10.
Eggermont
, J. J.
, and Don
, M.
(1980
). “Analysis of the click-evoked brainstem potentials in humans using high-pass noise masking. II. Effect of click intensity
,” J. Acoust. Soc. Am.
68
, 1671
–1675
.11.
Elberling
, C.
, Don
, M.
, Cebulla
, M.
, and Sturzebecher
, E.
(2007
). “Auditory steady-state responses to chirp stimuli based on cochlear traveling wave delay
,” J. Acoust. Soc. Am.
122
, 2772
–2785
.12.
Elberling
, C.
, and Wahlgreen
, O.
(1985
). “Estimation of auditory brainstem response, ABR, by means of Bayesian inference
,” Scand. Audiol.
14
, 89
–96
.13.
Elliott
, L. L.
(1965
). “Changes in the simultaneous masked threshold of brief tones
,” J. Acoust. Soc. Am.
38
, 738
–746
.14.
Fastl
, H.
, and Zwicker
, E.
(2007
). Psychoacoustics—Facts and Models
(Springer-Verlag
, Berlin
), 462
pp.15.
Finneran
, J. J.
, Branstetter
, B. K.
, Houser
, D. S.
, Moore
, P. W.
, Mulsow
, J.
, Martin
, C.
, and Perisho
, S.
(2014
). “High-resolution measurement of a bottlenose dolphin's (Tursiops truncatus) biosonar transmission beam pattern in the horizontal plane
,” J. Acoust. Soc. Am.
136
, 2025
–2038
.16.
Finneran
, J. J.
, Echon
, R.
, Mulsow
, J.
, and Houser
, D. S.
(2016a
). “Short-term enhancement and suppression of dolphin auditory evoked responses following echolocation click emission
,” J. Acoust. Soc. Am.
140
, 296
–307
.17.
Finneran
, J. J.
, Mulsow
, J.
, and Houser
, D. S.
(2013a
). “Auditory evoked potentials in a bottlenose dolphin during moderate-range echolocation tasks
,” J. Acoust. Soc. Am.
134
, 4532
–4547
.18.
Finneran
, J. J.
, Mulsow
, J.
, Houser
, D. S.
, and Burkard
, R. F.
(2016b
). “Place specificity of the click-evoked auditory brainstem response in the bottlenose dolphin (Tursiops truncatus)
,” J. Acoust. Soc. Am.
140
, 2593
–2602
.19.
Finneran
, J. J.
, Wu
, T.
, Borror
, N.
, Tormey
, M.
, Brewer
, A.
, Black
, A.
, and Bakhtiari
, K.
(2013b
). “Bottlenose dolphin (Tursiops truncatus) detection of simulated echoes from normal and time-reversed clicks
,” J. Acoust. Soc. Am.
134
, 4548
–4555
.20.
GraphPad Software
(2014
). “GraphPad Prism (Version 6) [computer software]
” (GraphPad Software, San Diego, CA).21.
Henson
, O. W.
, Jr. (1965
). “The activity and function of the middle-ear muscles in echo-locating bats
,” J. Physiol.
180
, 871
–887
.22.
Herdman
, A. T.
, Picton
, T. W.
, and Stapells
, D. R.
(2002
). “Place specificity of multiple auditory steady-state responses
,” J. Acoust. Soc. Am.
112
, 1569
–1582
.23.
Hoke
, M.
, Ross
, B.
, Wickesberg
, R.
, and Lutkenhoner
, B.
(1984
). “Weighted averaging—theory and application to electric response audiometry
,” Electroencephalogr. Clin. Neurophysiol.
57
, 484
–489
.24.
Masters
, W. M.
, and Jacobs
, S. C.
(1989
). “Target detection and range resolution by the big brown bat (Eptesicus fuscus)
,” J. Comp. Physiol. A
166
, 65
–73
.25.
Møhl
, B.
(1986
). “Detection by a pipistrelle bat of normal and reversed replica of its sonar pulses
,” Acustica
61
, 75
–82
.26.
Moore
, P. W. B.
, and Pawloski
, D. A.
(1990
). “Investigations on the control of echolocation pulses in the dolphin (Tursiops truncatus)
,” in Sensory Abilities of Cetaceans: Laboratory and Field Evidence
, edited by J. A.
Thomas
and R. A.
Kastelein
(Plenum
, New York
), pp. 305
–316
.27.
Nachtigall
, P. E.
(1980
). “Odontocete echolocation performance on object size, shape and material
,” in Animal Sonar Systems
, edited by R. G.
Busnel
and J. F.
Fish
(Plenum
, New York
), pp. 71
–95
.28.
Parker
, D. J.
, and Thornton
, A. R.
(1978
). “Frequency specific components of the cochlear nerve and brainstem evoked responses of the human auditory system
,” Scand. Audiol.
7
, 53
–60
.29.
Popov
, V.
, and Supin
, A. Y.
(1990
). “Electrophysiological studies of hearing in some cetaceans and a manatee
,” in Sensory Abilities in Cetaceans
, edited by J. A.
Thomas
and R. A.
Kastelein
(Plenum
, New York
), pp. 405
–415
.30.
Saillant
, P. A.
, Simmons
, J. A.
, Dear
, S. P.
, and McMullen
, T. A.
(1993
). “A computational model of echo processing and acoustic imaging in frequency-modulated echolocating bats: The spectrogram correlation and transformation receiver
,” J. Acoust. Soc. Am.
94
, 2691
–2712
.31.
Simmons
, J. A.
(2012
). “Bats use a neuronally implemented computational acoustic model to form sonar images
,” Curr. Opin. Neurobiol.
22
, 311
–319
.32.
Simmons
, J. A.
, and Gaudette
, J. E.
(2012
). “Biosonar echo processing by frequency modulated bats
,” IET Radar, Sonar Navig.
6
, 556
–565
.33.
Simmons
, J. A.
, Houser
, D.
, and Kloepper
, L.
(2014
). “Localization and classification of targets by echolocating bats and dolphins
,” in Biosonar
, edited by A.
Surlykke
, P. E.
Nachtigall
, R. R.
Fay
, and A. N.
Popper
(Springer-Verlag
, New York
), pp. 169
–193
.34.
Suga
, N.
, and Shimozawa
, T.
(1974
). “Site of neural attenuation of responses to self-vocalized sounds in echolocating bats
,” Science
183
, 1211
–1213
.35.
Supin
, A. Y.
, Nachtigall
, P. E.
, Pawloski
, J.
, and Au
, W. W. L.
(2003
). “Evoked potential recording during echolocation in a false killer whale Pseudorca crassidens
,” J. Acoust. Soc. Am.
113
, 2408
–2411
.36.
Teas
, D. C.
, Eldredge
, D. H.
, and Davis
, H.
(1962
). “Cochlear responses to acoustic transients: An interpretation of whole-nerve action potentials
,” J. Acoust. Soc. Am.
34
, 1438
–1459
.37.
Viemeister
, N. F.
, and Plack
, C. J.
(1993
). “Time analysis
,” in Human Psychophysics
, edited by W. A.
Yost
, A. N.
Popper
, and R. R.
Fay
(Springer-Verlag
, New York
), pp. 116
–154
.38.
Zwicker
, E.
(1965
). “Temporal effects in simultaneous masking by white-noise bursts
,” J. Acoust. Soc. Am.
37
, 653
–663
.2017
U.S. Government
You do not currently have access to this content.
