This study investigates the intensity and the duration of noise exposure to which a driver is subjected during actual freight hauling, over-the-road operation of cab-over-engine, intercity, diesel trucks on typical western interstate freeways. To do this, a practical instrument package was developed for recording dBA noise levels over extended periods of time. The noise levels produced during extended operation are compared with results of single decibel readings taken under various circumstances with the tractor stationary and accelerating. A determination is made as to whether the driver's occupational noise exposure is within the limits specified by Walsh-Healey for the various tractors tested.
