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(1968) hypotheses that clicks produced by the phonic lips propagate through a low-velocity core in the melon that po- sitions the emission path almost in the middle of the melon (Au et al., 2010).
An Appreciation
Heptuna’s studies described here are really. only a “sample” of the work he was engaged in over his 40-year Navy career. The References include many of the research papers that in- volved Heptuna, and there were also studies that were never published. But the point of this article is that this one animal made substantial contributions to our basic understanding of hearing and echolocation in dolphins. Indeed, Heptuna has become a “legend” in dolphin research. This status likely arose because one of the unique things about Heptuna and, what made him such a valuable animal, was that he learned new tasks remarkably quickly and that he was not easily frustrated. Moreover, he had a really good memory for past training, and he quickly adapted to new tasks based on simi- lar experiences in previous experiments, even many years earlier. And, although it is not quite “scientific” to say it, an- other thing that promoted Heptuna as an animal (and col- laborator) of choice was that he was, from the very beginning in 1971, an easy and friendly animal to work with, something not true of many other dolphins!
Acknowledgments
We thank Dorian Houser and Anthony Hawkins for valuable review of the manuscript. We also thank and acknowledge with great appreciation the many people mentioned in this article for their collaboration and work with Heptuna and the numerous other people who ensured the success of the Navy dolphin research program.
References
Anderson, S., Gordon-Salant, S., and Dubno, J. R. (2018). Hearing and ag- ing effects on speech understanding: Challenges and solutions. Acoustics Today 14(4), 10-18.
Au, W. W. L. (2015). History of dolphin biosonar research. Acoustics Today 11(4), 10-17.
Au, W. W. L. (1988). Dolphin sonar target detection in noise. The Journal of the Acoustical Society of America 84(S1), S133.
Au, W. W. L., Floyd, R. W., and Haun, J. E. (1978). Propagation of Atlantic bottlenose dolphin echolocation signals. The Journal of the Acoustical Soci- ety of America 64(2), 411-422.
Au, W. W. L., Houser, D. S., Finneran, J. J., Lee, W. J., Talmadge, L. A., and Moore, P. W. (2010). The acoustic field on the forehead of echolocating Atlantic bottlenose dolphins (Tursiops truncatus), The Journal of the Acous- tical Society of America 128, 1426-1434.
Au, W. W. L., and Moore, P. W. B. (1984). Receiving beam patterns and di-
rectivity indices of the Atlantic bottlenose dolphin (Tursiops truncatus).
The Journal of the Acoustical Society of America 75(1), 255-262.
Au, W. W. L., Moore, P. W. B., and Pawloski, D. A. (1986a). The preception of complex echoes by an echolocating dolphin. The Journal of the Acousti-
cal Society of America 80(S1), S107.
Au, W. W. L., Moore, P. W. B., and Pawloski, D. (1986b). Echolocation trans-
mitting beam of the Atlantic bottlenose dolphin. The Journal of the Acous-
tical Society of America 80(2), 688-691.
Au, W. W. L., and Penner, R. H. (1981). Target detection in noise by echolo-
cating Atlantic bottlenose dolphins. The Journal of the Acoustical Society of
America 70(3), 687-693.
Branstetter, B. K., Mercado, E., III, and Au, W. L. (2007). Representing
multiple discrimination cues in a computational model of the bottlenose dolphin auditory system. The Journal of the Acoustical Society of America 122(4), 2459-2468.
Brill, R. L., and Harder, P. J. (1991). The effects of attenuating returning echolocation signals at the lower jaw of a dolphin (Tursiops truncatus). The Journal of the Acoustical Society of America 89(6), 2851-2857.
Brill, R. L., Moore, P. W. B., and Dankiewicz, L. A. (2001). Assessment of dolphin (Tursiops truncatus) auditory sensitivity and hearing loss using jawphones. The Journal of the Acoustical Society of America 109(4), 1717-1722.
Caspers, P., and Müller, R. (2015). Eigenbeam analysis of the diversity in bat biosonar beampatterns. The Journal of te Acoustical Society of America 137(3), 1081-1087.
Ceruti, M. G., and Au, W. W. L. (1983). Microprocessor‐based system for monitoring a dolphin’s echolocation pulse parameters. The Journal of the Acoustical Society of America 73(4), 1390-1392.
Evans, W. (1967). Discrimination of different metallic plates by an echolo- cating delphinid. In R.-G. Busnel (Ed.), Animal Sonar Systems, Biology and Bionics. Laboratoire de Physiologie Acoustique, Jouy-en-Josas, France, vol. 1, pp. 363-383.
Houser, D., Martin, S. W., Bauer, E. J., Phillips, M., Herrin, T., Cross, M., Vidal, A., and Moore, P. W. (2005). Echolocation characteristics of free- swimming bottlenose dolphins during object detection and identification. The Journal of the Acoustical Society of America 117(4), 2308-2317.
Marten, K., Norris, K. S., Moore, P. W. B., and Englund, K. A. (1988). Loud impulse sounds in odontocete predation and social behavior. In P. E. Nachtigall and P. W. B. Moore (Eds.), Animal Sonar: Processes and Perfor- mance. Springer US, Boston, MA, pp. 567-579.
Moore, P. W. B., and Au, W. W. L. (1975). Underwater localization of pulsed pure tones by the California sea lion (Zalophus californianus). The Journal of the Acoustical Society of America 58(3), 721-727.
Moore, P. W. B., and Au, W. W. L. (1983). Critical ratio and bandwidth of the Atlantic bottlenose dolphin (Tursiops truncatus). The Journal of the Acous- tical Society of America 74(S1), S73.
Moore, P. W. B., and Brill, R. L. (2001). Binaural hearing in dolphins. The Journal of the Acoustical Society of America 109(5), 2330-2331.
Moore, P. W., Dankiewicz, L. A., and Houser, D. S. (2008). Beamwidth control and angular target detection in an echolocating bottlenose dol- phin (Tursiops truncatus). The Journal of the Acoustical Society of America 124(5), 3324-3332.
Moore, P. W. B., and Pawloski, D. A. (1990). Investigations on the control of echolocation pulses in the dolphin (Tursiops truncatus). In J. A. Thomas and R. A. Kastelein (Eds.), Sensory Abilities of Cetaceans: Laboratory and Field Evidence. Springer US, Boston, MA, pp. 305-316.
Moore, P. W., Pawloski, D. A., and Dankiewicz, L. (1995). Interaural time and intensity difference thresholds in the bottlenose dolphin (Tursiops truncatus). In R. A. Kastelein, J. A. Thomas, and P. E. Nachtigal (Eds.), Sensory Systems of Aquatic Mammals. DeSpil Publishers, Woerden, The Netherlands, pp. 11-23.
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