THE EFFECT OF AIR BUBBLES IN THE EXTERNAL AUDITORY MEATUS ON UNDERWATER HEARING THRESHOLDS.
FLORIDA UNIV GAINESVILLE COMMUNICATION SCIENCES LAB
Pagination or Media Count:
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 SPLs 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. SPLs 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
- Anatomy and Physiology
- Non-Radio Communications