Biological Effects of Sound in Mice

Abstract

Local and systemic changes were studied in hairless mice following irradiation of the integument with high intensity airborne sound. Comparisons were made between effects of subthermogenic (without skin heating) and thermogenic (skin heating) sound levels. Criteria, other than morphological, used in skin analyses included cytochemical examination of skin lipids, glycogen, PAS-reactive substances, and alkaline phosphatase. Failure to induce injury or any change in skin cytochemistry after local skin irradiation daily for three months with subthermogenic sound (18 kc, 150 db) indicated that direct effects of sound are negligible at these levels. The inflammatory response of skins exposed to higher sound levels (20 kc, 160–168 db) was found to result from local absorption of sound energy and its conversion into heat. Analysis of systemic effects included studies of changes in adrenal, hemopoietic, and reproductive organs. Skin treatment with subthermogenic sound produced no appreciable systemic response. A marked systemic reaction, however, always accompanied sound induced skin burns. Additional studies on effects of auditory stimulation on adrenals and eosinophils showed that prolonged exposure of mice to loud noise fields (10–20 kc, 110 db) proved to elicit only a mild systemic response. This work was sponsored in part by the Aero Medical Laboratory, Wright-Patterson Air Force Base, Dayton, Ohio, under contract No. AF 33(616)-2505