(Medical Xpress) -- More than half of factory workers who thought they had excellent or good hearing actually suffered hearing loss and didn't even recognize the problem, a new study shows.
The University of Michigan School of Nursing study found significant differences between measured and perceived hearing loss, and suggests health care providers need better methods of testing and protecting hearing among factory workers.
"This finding shows that even workers who are served by a workplace hearing conservation program and receive annual hearing testing may be unaware of their actual hearing ability," said Marjorie McCullagh, assistant professor in the U-M School of nursing and principal investigator. "Consequently, health care providers would be wise to examine methods to help workers develop more accurate perceptions of their hearing, and test more effective methods to protect it."
Of 2,691 noise exposed automobile factory workers surveyed for the study, 76 percent reported excellent or good hearing. However, after formal hearing tests, researchers found that that 42 percent of those workers actually suffered hearing loss. This indicates that self-reported hearing loss is poorly related to the results of audiometry, or formal hearing testing. In other words, many factory workers might have hearing loss and not even realize there's a problem, and the U-M findings are consistent with other studies demonstrating a discrepancy between measured and perceived hearing loss.
In the U-M Nursing study, hearing loss was highly prevalent among the workers despite a regulated work environment and a hearing conservation program. Noise represents one the nation's most common occupational health hazards.
The data was collected as part of an intervention study promoting hearing protector use among workers at a Midwest automotive factory.
Co-authors include Delbert Raymond, of Eastern Michigan University School of Nursing; Madeline Kerr, University of Minnesota School of Nursing; and Sally Lusk, U-M School of Nursing. The study appeared in the journal of Noise and Health.