Sounds like … hearing loss
Posted May 29, 2007
While sounds of the work locale can affirm that the job is getting done, they can also cause hearing loss and other health problems. But workplace sounds aren’t always the culprits. In 2000, William W. Clark, Ph.D., a professor of otolaryngology at Washington University in St. Louis, published an essay that examined common beliefs about our ability to hear and withstand loud noises during long stretches of time. Clark rebuffed the following noise myths:
A hearing loss configuration commonly called a ''noise notch'' refers to loss caused by or contributed to by noise exposure. Clark says such hearing loss is commonly seen in individuals with noise-induced hearing loss but can also be associated with other disorders, including viral infections, head trauma, and other health conditions.
Occupational noise exposure is the most significant cause of noise-induced hearing loss in the United States. According to The National Institute for Occupational Safety and Health, approximately 9 million American workers engaged in manufacturing or utilities are exposed to continuous noise exceeding 85 dB at least once per week during work hours. The same study shows that fewer than 1 million workers experience on-the-job noise exposures higher than 95 dB.
Occupational noise is far more hazardous than non-occupational noise. Although federal regulations have been in place for three decades, there are no regulations limiting hazardous exposure to noise outside the workplace, said Clark. Most reports of hearing loss from attending rock concerts, noisy restaurants, or movie watching tend to be false or exaggerated, he said, saying that firearms may play the heaviest role, with sound levels from rifles and shotguns between 132 dB and 172 dB or more
All loud leisure noise is dangerous noise. According to Clark, the risk of sustaining permanent hearing loss from attending rock concerts is small and is limited to people who frequently attend such events.
In 2001, the World Health Organization released its findings of a study on the health hazards behind occupational and non-occupational noise exposure. The report suggests that noise can cause hearing impairment, interfere with communication, disturb sleep, create cardiovascular and psycho-physiological effects, reduce performance, and provoke annoyance responses and changes in social behavior.
The report indicates that continuous exposure to an environmental average noise level of 70 dB will not cause hearing impairment for most people. Adults can tolerate an occasional noise level of up to 140 dB.
Among its workplace-specific findings, the World Health Organization report also lists impact processes, material handling, and industrial jets as major sources of noise with the potential to create hearing problems.
Exposure to sound in excess of 85 dB for more than 8 hours a day has the greatest potential for hazardous results, the report states. More specifically:
- Air jets, which are widely used for cleaning, drying, power tools, and steam valves, can generate sound levels of 105 dB.
- In the woodworking industry, the sound levels of saws can be as high as 106 dB.
- Average sound levels range between 92 dB and 96 dB in industries such as foundries, shipyards, breweries, weaving factories, and paper and saw mills. The recorded peak values were between 117 dB and 136 dB.
The National Institute of Occupational Safety and Health strongly advises two methods of occupational noise prevention: the use of engineering devices such as mufflers or acoustic barriers, and hearing loss prevention programs.