Noise exposure and hearing levels of workers in the sheet metal construction trade.

Hearing and noise levels were measured at a jobsite involving sheet metal construction work and at a sheet metal fabrication shop. Noise levels up to 114 dBA (slow response) were measured when various powered hand tools were used. Noise levels exceeded 85 dBA between one-fourth and one-third of the time. Impact noise levels averaged about 120-125 dB peak SPL. Audiometric examinations showed that this group of construction workers had hearing losses, with the majority of the loss occurring in the 3KH(Z) to 6 KH(Z) range. In addition the loss became more severe with increasing age. Temporary threshold shifts were observed both on the jobsite and in the shop after a single eight-hour exposure.