A Chinchilla Restraint System

Abstract : In studies of noise-induced hearing loss in chinchillas, it is necessary to restrain the animal in a known noise field for the duration of the exposure. In studies of continuous noise effects, a small cage in which the subject is free to move about has been used. The orientation of the subject due to the omnidirectional nature of continuous noise effects is not critical due to the omnidirectional nature of the exposure. In contrast, freefield impulse noise is a highly directional sound field by its essential nature. The need to restrain the research subject and fix its orientation relative to the source of the impulse is critical in impulse noise exposures. Only three references were found in the literature about chinchilla restraining devices. These devices were applicable more for routine clinical procedures, administering medication, detecting motion, and collecting motion, and collecting semen for reproduction studies. None were suited for auditory research. This led us to develop the chinchilla restraint system (CRSS). The function of the CRS is to maintain a chinchilla in a stable, immobile position which can be standardized for all subjects during studies of noise-induced hearing loss. The CRS accomplishes this using the chinchilla's own natural tendencies as a burrowing creature. The CRS provides an artificial burrow in which a chinchilla seems content to remain quiet for extended periods. This report details the design and use of the CRS.