Background: Exposure to noise has long been known to cause hearing loss, and is an ubiquitous problem in workplaces. Occupational noise exposures for industries stored in the Occupational Safety and Health Administration's (OSHA) Integrated Management Information System (IMIS) can be used to identify temporal and industrial trends of noise exposure to anticipate changes in rates of hearing loss. Methods: The noise records in OSHA's IMIS database for 1979-1999 were extracted by major industry division and measurement criteria. The noise exposures were summarized by year, industry, and employment size. Results: The majority of records are from Manufacturing and Services. Exposures in Manufacturing and Services have decreased during the period, except that PEL exposures measured by federal enforcement increased from 1995 to 1999. Conclusions: Noise exposures in manufacturing have been reduced since the late 1970s, except those documented by federal enforcement. Noise exposure data outside manufacturing is not well represented in IMIS.