Reduction in Audiogram Shifts in Sonar Watchstanders When Exposed to Surface Ship Echo-Ranging
Abstract
Audiograms collected underway on sonar technicians on USS GATO (SSN 615) during exposure to echo-ranging 19 - 31 January 1971 showed that SPLs in the sonar headsets may be hazardous to hearing. Two of three headsets were modified by NUSC/NLON so as to limit the peak SPLs delivered to the ear. On a cruise 21 - 31 March 1971, during which light to moderately heavy echo-ranging was encountered, 6 men using an unmodified headset, were exposed to SPLs up to 118 dB. In half the 12 ears a temporary hearing loss was found which exceeded a widely-disseminated damage-risk criterion. However, of 6 men who used modified headsets, no average loss whatever was found, and only 1 ear slightly exceeded the criterion. Whether the modification introduced on this occasion was an optimal compromise between protecting the ears vs obtaining all possible information from the sea, is still an open question. Further studies are in progress.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 21, 1971
- Accession Number
- AD0737207
Entities
People
- J. Donald Harris
- Paul G. Lacroix
Organizations
- Naval Submarine Medical Research Laboratory