Accession Number : AD0686073

Title :   THE EFFECT OF AIR BUBBLES IN THE EXTERNAL AUDITORY MEATUS ON UNDERWATER HEARING THRESHOLDS.

Descriptive Note : Progress rept.,

Corporate Author : FLORIDA UNIV GAINESVILLE COMMUNICATION SCIENCES LAB

Personal Author(s) : Hollien,Harry ; Brandt,John ; Doherty,E. Thomas

Report Date : 31 MAR 1969

Pagination or Media Count : 15

Abstract : Thresholds of human hearing were obtained underwater for two conditions: (1) with the external auditory meatus completely water filled and (2) with a bubble of air trapped against the tympanic membrane. The first condition was accomplished by forcibly irrigating the external meatus underwater; the second by placing plugs in the ears in order to encapsulate air in the meatus until the head was underwater and the test (with the plugs removed) initiated. Subjects were seven divers who were tested in DICORS at a depth of 12 ft.; threshold SPL's were obtained free-field by a modified Bekesy technique for the frequencies 125, 250, 1K, 2K, and 8K Hz. Threshold shifts (re: air) for both conditions of underwater hearing were consistant with those previously reported. SPL's for the two experimental conditions were virtually identical for all frequencies except 250 Hz where hearing was 6dB better for the water-filled meatus condition. Apparently, the presence of air bubbles in the external meatus contributes little if anything to underwater hearing thresholds. (Author)

Descriptors :   (*AUDITORY PERCEPTION, UNDERWATER), THRESHOLDS(PHYSIOLOGY), BUBBLES, PERFORMANCE(HUMAN), TEST EQUIPMENT, TEST METHODS, EAR, SPEECH, INTELLIGIBILITY

Subject Categories : Anatomy and Physiology
      Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE