High-frequency sound transmissions under water and risk of decompression sickness.
We tested the possible occurrence of a neurological insult secondary to high-frequency sound exposure. Immersed, anesthetized rats were subjected to a simulated diving profile designed to induce decompression sickness, while exposed to the transmission of an acoustic beacon. Intermittent sound at a pressure level of 184.5 dB re 1 microPa at 1 m (1.7 kPa), a frequency of 37 kHz, and with a duration of 4 ms, was transmitted in a duty cycle of 0.26%. Four groups, each containing nine animals, were included in the study as follows: group 1, immersion only, no sound exposure; group 2, immersion with sound exposure; group 3, diving simulation when immersed, no sound exposure; group 4, diving simulation when immersed, with sound exposure. Somatosensory evoked potentials (SSEPs) were recorded the day before the study, and a second recording was made 30 min after immersion. Some of the SSEP components disappeared after the dive in 3 rats from group 3 and 2 rats from group 4. SSEP components could not be identified in a significantly larger number of animals from groups 3 and 4, compared with groups 1 and 2. No differences were found in wave latency, amplitude or conduction time. Our data show that the high-frequency sound exposure employed did not contribute to the development of the neurological insult.
Shupak
Avi
A
Israel Naval Medical Institute, IDF Medical Corps, Haifa, Israel. shupak@internet-zahav.net
Pratt
Hillel
H
Arieli
Yehuda
Y
Tal
Dror
D
D000818:Animals; D003665:Decompression Sickness / Q000209:etiology*; D004242:Diving; D005073:Evoked Potentials, Somatosensory; D008297:Male; D023421:Models, Animal; D051381:Rats; D017207:Rats, Sprague-Dawley; D012306:Risk; D014465:Ultrasonics / Q000009:adverse effects*