Hearing Loss
Repeated exposures to loud noise can lead to permanent, incurable hearing loss or tinnitus [NIOSH 2002a]. Approximately 30 million workers are exposed to hazardous noise on the job, and an additional 9 million are at risk for hearing loss from other agents such as solvents and metals [NIOSH 2002b]. From 1992 to 2000 (and beginning again in 2002), NIOSH provided technical and financial support through the SENSOR program to the State of Michigan for a noise-induced hearing loss surveillance and prevention program. The Michigan SENSOR program is a partnership between the Michigan Department of Labor and Economic Growth and the Michigan State University [Rosenman et al. 2002].
Data for the figures come from Michigan’s surveillance reports, including reports from audiologists, otolaryngologists, and companies. A worker is considered to have occupational noise-induced hearing loss if a health professional determines the worker to have (a) audiometric findings consistent with noise-induced hearing loss, and (b) a history of exposures to sufficient noise at work to cause hearing loss. In 2000, Michigan reported more than 2,200 new hearing loss cases known or suspected to be caused by noise at work.
Reporting Sources
Who reported occupational noise-induced hearing loss during 1991–2000?
 | Figure 2-29 Distribution and number of noise-induced hearing loss cases in Michigan by source of reports, 1991-2000. During 1991-2000, 17,683 noise-induced hearing loss cases were reported in Michigan. Companies with hearing conservation programs reported the largest number of workers with occupational noise-induced hearing loss. Typically, companies reported standard threshold shifts, whereas the other three sources reported fixed losses of at least 25 dB. (Source: Rosenman and Reilly [2002].) |
Age
How old were workers who developed occupational noise-induced hearing loss in 2000?
 | Figure 2-30 Distribution of noise-induced hearing loss cases in Michigan by age of patient and type of report (company or noncompany), 2000. Company reports indicated that workers aged 40-49 and 50-59 had the highest percentages of noise-induced hearing loss cases (36% and 33.8%, respectively) in 2000. Noncompany and company reports indicated nearly equal percentages of cases among workers aged 50-59. Age was unknown for 11 workers reported by company medical departments and for 40 workers reported by noncompany hearing health professionals. The hearing loss reports from companies involve a younger working age population enrolled in a hearing conservation program. (Source: Rosenman and Reilly [2002].) |
Industry
Where were workers with occupational noise-induced hearing loss exposed to the noise that caused their hearing loss?
 | Figure 2-31 Distribution and number of permanent hearing loss cases reported by clinicians in Michigan, by industry, 2000. Manufacturing accounted for 50.9% of permanent hearing loss cases reported in Michigan in 2000, and construction industry sectors accounted for 15.0%. (Source: Rosenman and Reilly [2002].) |
In which industries were companies most likely to test for hearing loss as part of a hearing conservation program?
 | Figure 2-32 Percentage of companies in Michigan in major industry divisions that tested for hearing loss as part of a hearing conservation program (when worker was most recently exposed to noise), as reported by patient interviews, 1992-2000. Companies were most likely to have tested for hearing loss as part of a hearing conservation program (when worker was most recently exposed to noise) in the transportation, manufacturing, and mining industries. (Source: Rosenman and Reilly [2002].) |
