Test chamber for determining damage thresholds for high-amplitude underwater sound exposure in animal models

Abstract

In order to determine the effects of low frequency underwater sound on small animal models, it is desirable to expose them to well characterized fields which closely simulates the (locally) plane wave open ocean stimulus. It is also desirable to produce pure pressure and acceleration stimuli to isolate the effects of the individual components of the acoustic p]ane wave. It is necessary to produce sufficiently strong signals to enable damage thresholds to be determined. The range of frequencies over which such stimuli must be produced is quite broad since it must include the actual band of interest (100-500 W) to examine damage on the cellular and tissue level. as well as at scaled frequencies (-l-5 W) to examine the effects of organ structure. The problem is subtler than one might imagine because of the high compliance of the test animals due to the high compliance of the test animals due to air in their lungs. Careful consideration is required to ascertain what is required of the chamber to assure valid measurements and to determine the true effective sound pressure level.

Threshold for Onset of Injury in Chinook Salmon from Exposure to Impulsive Pile Driving Sounds

“…Plane-wave acoustic conditions are those that exist at distances greater than a few meters from any sound source such as pile driving or a survey vessel. Thus, to meet these challenges, this study required the development of a specially designed wave tube called a High Intensity Controlled Impedance – Fluid filled wave Tube (HICI-FT) [11] , [12] , see Figure 1 . The HICI-FT provided the capacity to expose aquatic animals, such as fish and invertebrates, to impulsive sound under far-field, plane-wave acoustic conditions.…”