Developing acoustical criteria for rodent housing facilities.

Abstract

Medical researchers often use mice and rats for numerous procedures. In typical rat housing rooms, there can be as many as 200 rats for an investment of $800,000 and in typical mouse rooms, as many as 2570 mice for an investment of $10 million. Do the sound and ultrasound exposures of these animals interfere with the medical research objectives of the scientists? Research has shown that high-noise levels have an effect on the physical and psychological responses of rodents. In order to eliminate this factor from influencing the medical experiments, criteria limiting noise and ultrasound in animal-housing facilities are needed. Mice have a hearing range of 1000–91 000 Hz, rats from 200 to 76 000 Hz, and other rodents can hear well above the human threshold. This makes creating a standard even more important because the majority of the frequencies perceived by rodents, including frequencies in which they communicate, are not perceptible to humans and therefore cannot be easily assessed. This study considers typical environments where these animals are housed, the levels at which mice are effected by noise and ultrasound, and the existing guidelines in non-US countries. Preliminary noise and ultrasound criteria are presented.