Page 30 - Spring2022

UNDERWATER HEARING IN HUMANS
Figure 5. NSMRL human torso simulant (QUantitative Instrumented Torso [QUINT]; left) used to predict impact of high-energy, impulsive sources on internal organs (right).
Conclusions
We have presented an overview of the field of underwater hearing. Although not every topic could be covered in detail, our goal was to provide a general understanding of how human hearing underwater is different than that in air and what humans’ underwater hearing capabilities are. Exposure to loud sounds underwater is a concern for divers, and in many situations, the limited hearing protection that is available is not effective. The NSMRL continues to conduct research to improve safety guidance for Navy divers, but our efforts would not be possible without standing on the shoulders of all the scientists who established the field before us.
Acknowledgments
The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, nor the US Government. We are employees of the US Government. This work was prepared as part of our official duties. Title 17 U.S.C. §105 provides that
“Copyright protection under this title is not available for any work of the United States Government.” Title 17 U.S.C. §101 defines a US Government work as a work prepared by an employee of the US Government as part of that person’s official duties.
References
Al-Masri, M., and Martin, A. (1996). Underwater hearing and occupational noise exposure. In Axelsson, A., Hellstrom,P., A., Borchgrevink, H. M., Henderson, D., Hamernik, R. P., and Salvi, R. J. (Eds.), Scientific Basis of Noise-Induced Hearing Loss. Thieme Medical Publishers, New York, NY, pp. 119-133.
Brandt, J. F., and Hollien, H. (1967). Underwater hearing thresholds in man. The Journal of the Acoustical Society of America 42, 966-971. Clark, W. W. (1991). Recent studies of temporary threshold shift
(TTS) and permanent threshold shift (PTS) in animals. The Journal
of the Acoustical Society of America 90, 155-163.
Cudahy., E., and Parvin, S. (2001). The Effects of Underwater Blast on
Divers. Technical Report 1218, Naval Submarine Medical Research
Laboratory, Groton, CT.
Curley, M. D., and Knafelc, M. E. (1987). Evaluation of noise within
the MK 12 SSDS helmet and its effect on divers’ hearing. Undersea
Biomedical Research 14, 187-204.
Fay, R. R., and Popper, A. N. (2000). Evolution of hearing in verte-
brates: The inner ears and processing. Hearing Research 149, 1-10 Feinstein, S. H. (1973). Acuity of the human sound localization response underwater. The Journal of the Acoustical Society of America
53, 393-399.
Fothergill, D. M., Cudahy, E. A., Schwaller, D. W., Townsend, O.,
and Qin, M. K. (2018). Psychophysical Measurements of a Neoprene Wetsuit Hoods Sound Attenuation as a Function of Dive Depth and Frequency: Hyperbaric Chamber Trials. Technical Report 1325, Naval
Submarine Medical Research Laboratory, Groton, CT.
Fothergill, D. M., Schwaller, D., Forsythe, S. E., and Cudahy, E. A. (2002). Recreational Diver Responses to 600-2500 Hz Waterborne
Sound. Technical Report 1223, Naval Submarine Medical Research
Laboratory, Groton, CT.
Hamilton, P. M. (1957). Underwater hearing thresholds. The Journal
of the Acoustical Society of America 29, 792-794.
Hollien, H., and Brandt, J. F. (1969). Effect of air bubbles in the exter-
nal auditory meatus on underwater hearing thresholds. The Journal
of the Acoustical Society of America 46, 384-387.
Hollien, H., and Feinstein, S. (1975). Contribution of the external
auditory meatus to auditory sensitivity underwater. The Journal of
the Acoustical Society of America 57, 1488-1492.
Ide, J. (1944). Signalling and Homing by Underwater Sound; for Small
Craft and Commando Swimmers. Sound Report 19, Naval Research
Laboratory, Washington, DC.
International Standards Organization (1993). Acoustics-Equal Loudness Level
Contour for Otologically Normal Listeners, Part 1: Reference Threshold of Hearing Under Free-Field and Diffuse Field Listening Conditions. ISO/CD 226-2, International Standards Organization, Geneva, Switzerland.
30 Acoustics Today • Spring 2022