Since World War II, the human and financial costs associated with hearing loss among military veterans have repeatedly drawn attention to noise and the need for hearing conservation in military settings. In recent years, noise-related tinnitus has also emerged as a significant concern. In 2002, Congress directed the Department of Veterans Affairs to contract with the National Academies for a study of noise-induced hearing loss and tinnitus associated with military service from World War II to the present. The Institute of Medicine of the National Academies convened a 13-member committee to conduct this study and to review: (1) available data on hearing loss that could be expected in the armed forces; (2) sources of hazardous noise exposure during military service; (3) levels of noise exposure necessary to cause hearing loss or tinnitus; (4) the time course, including possible delayed onset, of hearing loss following noise exposure; (5) risk factors for noise-induced hearing loss and tinnitus; and (6) compliance with requirements for audiometric testing and the adequacy of the services' hearing conservation programs. The report issued in September 2005. The findings, summarized herein, include evidence suggesting that the use of hearing protection was and still is inadequate, that incomplete reporting or unsatisfactory compliance with audiometric testing requirements has impaired the usefulness of the military audiometric databases, and that military hearing conservation programs have not been adequate since World War II. The report cites efforts to address noise exposure among military personnel, but observes that more must be done to make the programs effective.