Efforts to determine the number of workers exposed to occupational noise were reviewed. Three surveys had been conducted to determine the number of workers who were exposed to hazardous workplace noise, to determine the industries in which they worked, and to determine the distribution of noise levels among the workers. The three surveys were the National Occupational Hazard Survey (NOHS) conducted between 1974 and 1978 to determine the prevalence of noise exposure in industry and the availability of employer provided hearing conservation programs; the Bolt, Beranek, and Newman Study conducted in 1976 which studied the impact of noise on society and the impact of the amendment for noise control on business; and the Booz, Allen, and Hamilton Study commissioned in 1983 to determine the technical and economic impact of setting an alternative noise standard. The three surveys used different strategies and different references for estimates of the total workforce size. The NOHS study concluded that 37 percent of all workers exposed to continuous noise received some type of periodic audiometric testing with the tobacco industry providing the highest coverage at 97 percent and the apparel industry the lowest at 1 percent. The author concludes that it is vital that surveys of noise, hearing loss incidence, and hearing conservation programs be properly designed and carried out periodically to assess progress in preserving workers' hearing.