Accession Number : AD0649669

Title :   UNDERWATER HEARING THRESHOLDS IN MAN.

Descriptive Note : Progress rept. no. 3,

Corporate Author : FLORIDA UNIV GAINESVILLE COMMUNICATION SCIENCES LAB

Personal Author(s) : Brandt,John F. ; Hollien,Harry

Report Date : 01 APR 1967

Pagination or Media Count : 22

Abstract : The audibility threshold performance of the human ear submerged in water at ear depths of 12 and 35 feet was compared to its performance in air. Threshold SPLs at 125, 250, 500, 1000, 2000, 4000, and 8000 Hz from 5 male and 3 female divers wearing open circuit SCUBA equipment were obtained by the Bekesy technique. Differences between water and air conduction thresholds ranged from 18 dB SPL re 0.0002 microbar at 125 Hz to 56 dB at 8000 Hz. Water conduction thresholds ranged from between 58 and 74 dB SPL with maximum sensitivity around 500 Hz. Maximum sensitivity for air conduction thresholds was obtained at 2000 Hz. Slightly higher thresholds were obtained at the 35 foot depth than at the 12 foot depth (about 1 dB at 250 Hz and 10 dB at 8000 Hz). Threshold SPL for male divers tended to be lower than female divers below 1000 Hz but higher than female divers above 8000 Hz in both air and water. Tentatively data suggest the importance of bone conduction mechanisms in underwater hearing. (Author)

Descriptors :   (*VOICE COMMUNICATIONS, UNDERWATER), (*HEARING, THRESHOLDS(PHYSIOLOGY)), SPEECH, INTELLIGIBILITY, PSYCHOACOUSTICS, AUDIO FREQUENCY, SCUBA DIVERS, SENSITIVITY, BONES, CONDUCTIVITY, SPEECH RECOGNITION, SOUND TRANSMISSION, UNDERWATER SOUND, AUDIOMETRY

Subject Categories : Psychology
      Acoustics
      Voice Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE