Auditory Temporary Threshold Shift in Snowmobile Users

Abstract

It has been determined that the noise levels of many snowmobiles and other all-terrain-vehicles frequently exceed criterion values of safe exposure as a function of time. However, there are obvious limitations to the use of the CHABA criteria for determining hazardous noise exposure, since typical snowmobile use does not approximate the extent of exposure implied by the “working-lifetime” concept. Thus, the empirical determination of the amount of TTS resulting from “typical” exposures, whatever they may be, seemed to provide a more relevant approach to the question of whether snowmobile noise poses a hazard to hearing acuity of operators and passengers. TTS measurements were obtained on a number of individuals of all ages under field conditions (within 1–15 min of termination of exposure). Significant amounts of TTS were observed to be occurring in a large proportion of the persons tested. The implications of this study are discussed in terms of the users, the manufacturers, and the CHABA criteria for hazardous noise exposure.