NIOSH testimony on noise by J. F. Finklea, A. Cohen and T. L. Henderson, July 23, 1975.
This joint testimony before the Subcommittee of the Senate Small Business Committee concerned the effects of industrial noise pollution on human health and the actions taken by NIOSH to protect the nation's workers against this hazard. A criteria document was issued in 1972 as a key step in a regulatory process still in motion. Evidence has been discovered which links exposure to occupational noise with hearing loss, interference with the reception of other desired sounds, physiological and psychological disturbances, and the disturbance of work performance and behavior. Field surveys have been undertaken on noise and hearing in different occupations. The retention of 90 decibels as the recommended exposure limit for an 8 hour workday, with higher levels permitted for shorter durations was discussed. The suggestion was made that this be lowered to 85 decibels soon. Available laboratory studies indicated that performance error in noise is most likely to occur when there is a combination of conditions consisting of high level interrupted sounds, a fast paced, difficult task and tense or anxious individuals. A change in behavior is most clearly seen in the startle response provoked by unexpected, loud explosive like sounds. The study of extra auditory effects of noise exposure has increased in recent years including stress with its changes in cardiovascular, endocrine, neurological and other physiologic functions. Noise control handbooks were being prepared which will describe the properties of materials available for noise reduction, and case histories of engineering solutions to noise problems.