Some Biological Effects of Intense High Frequency Airborne Sound

Abstract

Some expts. have been conducted to determine the effect of intense high frequency airborne sound on mice and a variety of insects. The sound source was a high frequency siren. The frequency used was about 20 kc and its acoustic level, in the region where the subjects were placed, was between 160 and 165 db (relative to 10-16 watts/cm.2). With sufficient exposure[long dash]from 10 sec. for flies and mosquitoes to 3 or 4 minutes for roaches and caterpillars[long dash]the sound proved lethal in all cases. More detailed work was performed on mice and the roach, Peri-planeta americana. In both cases it was established that the heating produced by sound absorption was sufficient to cause death. In addition to the heating there are other effects, notably tissue rupture, as evidenced by the almost complete destruction of the wings on flies and mosquitoes and the rapid deterioration and final disappearance of the external pinna of the mouse which had received a sub-lethal dose. During observations it has been impossible completely to avoid personal exposure to the sound field and some of the effects observed under these conditions will be described. These include momentary dizziness, and heating of exposed parts of the hand.