Underwater sound beacons (pingers) are employed in professional and scientific diving for location and navigation. Previous studies have demonstrated that exposure to acoustic fields may lead to the emergence of bubbles and cavities in tissues by rectified diffusion. However, this issue was studied mainly in vitro in various gels and isolated tissues. In the present study, we used the intact prawn Palaemon elegans, whose transparent shell makes it possible to conduct continuous microscopic observation of gas-bubble dynamics in the intact living prawn, to study the effect of high-frequency sound. In a crossover designed experiment, prawns were exposed to hyperbaric pressure of 203 kPa for 10 min, followed by decompression at 40 m/min (control). This procedure was carried out in the study group during transmission of a 37-kHz, 0.25-W, 10-ms pulse width, 1 pulse/s pulse interval. A significant increase was found in the mean volume of bubbles present for a longer period of time, in a higher percentage of the high-frequency sound-exposed prawns. We suggest that this sound exposure causes more gaseous micronuclei to grow into bubbles, and more of the dissolved gas to shift into the gas phase.
Bibliographical noteFunding Information:
The authors thank Giora Rosenhause, for consultation in mathematical aspects in acoustics, and Richard Lincoln, for skillful editing. This research was financed by the PADI Foundation (Beverly Hills, CA).
- Decompression sickness
- Gas bubble
- High-frequency sound
- Rectified diffusion
ASJC Scopus subject areas
- Radiological and Ultrasound Technology
- Acoustics and Ultrasonics