Noise at work--tolerable limits and medical control.

An attempt is made to assign TLV's to noise in a manner similar to that used by the ACGIH for chemical substances. Based on these criteria and available data, it would appear that the TLV-TWA for noise should be less than 65 dBA. Since it is unlikely that this limit will be accepted at any time in the near future, another approach is necessary. It is suggested that the expected degree of social hearing impairment at age 70-75 be used as the control criteria. To establish a connection between hearing-loss and social hearing impairment, exposure data developed by Passchier-Vermeer and Robinson were correlated with presbycusis data reported by Spoor for the period following exposure. It can be shown that, even with a limit of 80 dBA, noise induced social hearing impairment among the elderly could be expected in 10% of the population. It should be the function of the Occupational Health Services to identify these people by means of audiometric testing.