263
Chapter eleven: Acoustics
in terrestrial mammals? Are the tympanic membrane and external acoustic meatus and
canal vestigial, having lost their function in the transition to a fully aquatic lifestyle? Is
hearing achieved by passage of the sound directly to the cochlear capsule, which produces
differential motion between the cochlear capsule and the footplate of the stapes such that
displacement of the cochlear fluids occurs?
Even with relatively extensive study, there remains much to be discerned about hearing in odontocetes, and marine mammals as a whole. Certainly, the return to the marine
environment, either fully or amphibiously, has resulted in modifications to both sound
production and sound reception systems. The degree of anatomical modification supporting these changes is broad, ranging from reductions of terrestrial traits (e.g., reduced
but present pinna of some pinnipeds) to major rearrangements of the terrestrial bauplän
(e.g., separation of the auditory bullae from the skull in cetaceans). How these changes
relate to hearing capabilities and physiological function will remain research questions for
years to come, and they will have an increasing importance related to conservation issues
as it relates to human-caused sound in the world’s oceans.
References
Alderson, A.M., E. Diamantopoulos, and C.B.B. Downman. 1960. Auditory cortex of the seal (Phoca
vitulina). Journal of Anatomy 94:506–511.
Amundin, M. and S.H. Andersen. 1983. Bony nares air pressure and nasal plug muscle activity during click production in the harbour porpoise, Phocoena phocoena, and the bottlenosed dolphin,
Tursiops truncatus. Journal of Experimental Biology 105 (1):275–282.
Au, W.W.L. and M.C. Hastings. 2008. Principles of Marine Bioacoustics. New York: Springer.
Au, W.W.L., R.A. Kastelein, K.J. Benoit-Bird, T.W. Cranford, and M.F. McKenna. 2006. Acoustic radiation from the head of echolocating harbor porpoises (Phocoena phocoena). Journal of Experimental
Biology 209 (Part 14):2726–2733.
Au, W.W.L. and P.W.B. Moore. 1984. Receiving beam patterns and directivity indices of the Atlantic
bottlenosed dolphin (Tursiops truncatus). Journal of the Acoustical Society of America 75 (1):255–262.
Babushina, E.S. and M.A. Poliakov. 2004. The underwater and airborne horizontal localization of
sound by the northern fur seal. Biofizika 49 (4):723–726.
Boddy, A.M., M.R. McGowen, C.C. Sherwood, L.I. Grossman, M. Goodman, and D.E. Wildman.
2012. Comparative analysis of encephalization in mammals reveals relaxed constraints on
anthropoid primate and cetacean brain scaling. Journal of Evolutionary Biology 25:981–994.
Bodson, A., L. Miersch, and G. Dehnhardt. 2007. Underwater localization of pure tones by harbor
seals (Phoca vitulina). Journal of the Acoustical Society of America 122 (4):2263–2269.
Bodson, A., L. Miersch, B. Mauck, and G. Dehnhardt. 2006. Underwater auditory localization
by a swimming harbor seal (Phoca vitulina). Journal of the Acoustical Society of America 120
(3):1550–1557.
Branstetter, B.K., S.J. Mevissen, L.M. Herman, A.A. Pack, and S.P. Roberts. 2003. Horizontal angular
discrimination by an echolocating bottlenose dolphin Tursiops truncatus. Bioacoustics 14:15–34.
Branstetter, B.K., J.S. Trickey, K. Bahktiari, A. Black, H. Aihara, and J.J. Finneran. 2013. Auditory
masking patterns in bottlenose dolphins (Tursiops truncatus) with natural, anthropogenic, and
controlled noise. Journal of the Acoustical Society of America 133 (3):1811–1818.
Brill, R.L. and P.J. Harder. 1991. The effects of attenuating returning echolocation signals at the lower
jaw of a dolphin (Tursiops truncatus). Journal of the Acoustical Society of America 89 (6):2851–2857.
Brumm, H. and S.A. Zollinger. 2013. Avian vocal production in noise. In Animal Communication and
Noise, ed. H. Brumm. Berlin, Germany: Springer-Verlag.
Bullock, T.H., D.P. Domning, and R.C. Best. 1980. Evoked brain potentials demonstrate hearing in a
manatee (Trichechus inunguis). Journal of Mammalogy 61 (1):130–133.
Bullock, T.H., S.H. Ridgway, and S. Nobuo. 1971. Acoustically evoked potentials in midbrain auditory structures in sea lions (Pinnipedia). Zeitshchrift für Vergleichende Physiologie 74:372–387.
Chapter eleven: Acoustics
in terrestrial mammals? Are the tympanic membrane and external acoustic meatus and
canal vestigial, having lost their function in the transition to a fully aquatic lifestyle? Is
hearing achieved by passage of the sound directly to the cochlear capsule, which produces
differential motion between the cochlear capsule and the footplate of the stapes such that
displacement of the cochlear fluids occurs?
Even with relatively extensive study, there remains much to be discerned about hearing in odontocetes, and marine mammals as a whole. Certainly, the return to the marine
environment, either fully or amphibiously, has resulted in modifications to both sound
production and sound reception systems. The degree of anatomical modification supporting these changes is broad, ranging from reductions of terrestrial traits (e.g., reduced
but present pinna of some pinnipeds) to major rearrangements of the terrestrial bauplän
(e.g., separation of the auditory bullae from the skull in cetaceans). How these changes
relate to hearing capabilities and physiological function will remain research questions for
years to come, and they will have an increasing importance related to conservation issues
as it relates to human-caused sound in the world’s oceans.
References
Alderson, A.M., E. Diamantopoulos, and C.B.B. Downman. 1960. Auditory cortex of the seal (Phoca
vitulina). Journal of Anatomy 94:506–511.
Amundin, M. and S.H. Andersen. 1983. Bony nares air pressure and nasal plug muscle activity during click production in the harbour porpoise, Phocoena phocoena, and the bottlenosed dolphin,
Tursiops truncatus. Journal of Experimental Biology 105 (1):275–282.
Au, W.W.L. and M.C. Hastings. 2008. Principles of Marine Bioacoustics. New York: Springer.
Au, W.W.L., R.A. Kastelein, K.J. Benoit-Bird, T.W. Cranford, and M.F. McKenna. 2006. Acoustic radiation from the head of echolocating harbor porpoises (Phocoena phocoena). Journal of Experimental
Biology 209 (Part 14):2726–2733.
Au, W.W.L. and P.W.B. Moore. 1984. Receiving beam patterns and directivity indices of the Atlantic
bottlenosed dolphin (Tursiops truncatus). Journal of the Acoustical Society of America 75 (1):255–262.
Babushina, E.S. and M.A. Poliakov. 2004. The underwater and airborne horizontal localization of
sound by the northern fur seal. Biofizika 49 (4):723–726.
Boddy, A.M., M.R. McGowen, C.C. Sherwood, L.I. Grossman, M. Goodman, and D.E. Wildman.
2012. Comparative analysis of encephalization in mammals reveals relaxed constraints on
anthropoid primate and cetacean brain scaling. Journal of Evolutionary Biology 25:981–994.
Bodson, A., L. Miersch, and G. Dehnhardt. 2007. Underwater localization of pure tones by harbor
seals (Phoca vitulina). Journal of the Acoustical Society of America 122 (4):2263–2269.
Bodson, A., L. Miersch, B. Mauck, and G. Dehnhardt. 2006. Underwater auditory localization
by a swimming harbor seal (Phoca vitulina). Journal of the Acoustical Society of America 120
(3):1550–1557.
Branstetter, B.K., S.J. Mevissen, L.M. Herman, A.A. Pack, and S.P. Roberts. 2003. Horizontal angular
discrimination by an echolocating bottlenose dolphin Tursiops truncatus. Bioacoustics 14:15–34.
Branstetter, B.K., J.S. Trickey, K. Bahktiari, A. Black, H. Aihara, and J.J. Finneran. 2013. Auditory
masking patterns in bottlenose dolphins (Tursiops truncatus) with natural, anthropogenic, and
controlled noise. Journal of the Acoustical Society of America 133 (3):1811–1818.
Brill, R.L. and P.J. Harder. 1991. The effects of attenuating returning echolocation signals at the lower
jaw of a dolphin (Tursiops truncatus). Journal of the Acoustical Society of America 89 (6):2851–2857.
Brumm, H. and S.A. Zollinger. 2013. Avian vocal production in noise. In Animal Communication and
Noise, ed. H. Brumm. Berlin, Germany: Springer-Verlag.
Bullock, T.H., D.P. Domning, and R.C. Best. 1980. Evoked brain potentials demonstrate hearing in a
manatee (Trichechus inunguis). Journal of Mammalogy 61 (1):130–133.
Bullock, T.H., S.H. Ridgway, and S. Nobuo. 1971. Acoustically evoked potentials in midbrain auditory structures in sea lions (Pinnipedia). Zeitshchrift für Vergleichende Physiologie 74:372–387.