More than 30 million Americans have hearing loss, and noise in the workplace is by far the biggest factor in causing massive hearing loss in the work population, according to Maurice Miller, professor of audiology at New York University.
Workers in manufacturing industries are especially vulnerable. More than 5 million workers in various manufacturing industries are exposed to average daily noise levels of 85 decibels (dB) or more, enough to produce significant hearing loss over a lifetime of work, Miller said.
"While noise-induced hearing loss (NIHL) is completely irreversible, it is also completely preventable," said Ed Stevenson, director of industrial hygiene at Liberty Mutual. Yet, despite the prevalence of this very preventable problem, many experts complain that there is a widespread complacency about hearing loss in the business community.
"Nobody dies from it, ears don't bleed, and there is the expectation that you will lose your hearing anyway," said Mark Stephenson, a bioacoustics researcher at the National Institute for Occupational Safety and Health (NIOSH).
Carol Merry, a NIOSH specialist in hearing loss prevention, said one thing stood out at a recent best practices conference on hearing conservation in Michigan. "There was frustration on the part of the people attending," Merry said. "Occupational hearing is such a huge problem affecting so many people; yet, one of my colleagues joked, 'Like Rodney Dangerfield, hearing loss don't get no respect.' "
One reason for the lack of concern is that only a fraction of actual occupational hearing loss is evident, experts say, due to the poor system used to record occupational illnesses. "We don't have a good system for collecting data on occupational illnesses," said Dr. Kenneth Rosenman, a professor of medicine at Michigan State University. "The Bureau of Labor Statistics is focused on injuries, and the OSHA log system is totally inadequate."
A five-year comprehensive study of occupational NIHL in Michigan conducted by Rosenman is attracting national attention because it shows that the problem of occupational hearing has often been underreported. Michigan is the only jurisdiction that requires all health providers to report to the state all occupational illnesses, including hearing loss. Few people were aware of the law, Rosenman said, until 1988, when the state began a comprehensive outreach program to encourage workers and health practitioners to report cases of occupational hearing loss. What followed was an enormous increase in new occupational hearing loss reports beginning in 1989.
Despite these efforts, many cases of occupational NIHL in Michigan are not being reported, according to Rosenman. "We're still getting a relatively small percentage of the problems that are out there," he said.
Rosenman's study also revealed that a large number of small and large companies have no hearing conservation programs, despite a need for them. The numbers for "Non-Company Reports" show that, over the last five years, between 307 and 488 workers with reported NIHL were in companies with no hearing conservation program.
Michigan's OSHA used the study's revelations to inspect the companies without hearing conservation programs. OSHA officials in Washington also took notice. "I consider the Michigan data to be the tip of the iceberg," said OSHA's Maddux. The No. 1 cause for OSHA noise citations is that companies with noise levels above 85 dB have no hearing conservation program, according to Craig Moulton, who works in OSHA's Office of Health Compliance Assistance.
It is not OSHA inspections, but the unpredictable costs of defending against litigation for hearing loss that ought to concern a company the most, warns John Earshen, president of Angevine Acoustical Consultants Inc., East Aurora, N.Y. He said a company can go for years without seeing an OSHA inspector, but if hearing damage occurs, a firm may face not just workers' compensation claims, but lawsuits if the damage is the result of egregious action or gross negligence.
Protecting the Ears
There are essentially two ways to prevent NIHL in the workplace: reduce the noise or protect the ears of the worker. Traditionally, most companies have opted for hearing protectors because this approach initially appears to be less expensive than reducing noise through engineering controls. Many experts question this approach.
Since 1983, OSHA has required hearing conservation programs if workers are exposed to an average of 85 dB per day. But according to NIOSH's Merry, many companies with such programs are concerned that workers are continuing to lose their hearing. "Some programs," she said, "have done little more than document the progression of hearing loss."
"We're simply seeing more hearing loss in the population than we would expect if these programs were effective," said Liberty Mutual's Stevenson. Rosenman agrees, pointing to data from his study that shows the vast majority of workers in Michigan with NIHL are already in company hearing conservation programs.
"The fact that we're getting an average of 1,500 cases a year of NIHL from workers in hearing conservation programs," Rosenman said, "suggests there's a problem with the effectiveness of some of these programs."
A hearing conservation program must: 1) survey the workplace to establish if a hazard exists and where; 2) institute a training program consisting of hazard awareness, motivation, hearing protection and instruction on how to use the protectors; and 3) monitor the program for its effectiveness by testing workers' hearing and making sure they are wearing protectors.
NIOSH has been interested for some time in why workers are continuing to lose their hearing in hearing conservation programs, Merry said. She stressed the importance of tailoring each training program to the individual workplace.
"It's not good enough to take a commercial canned video off the shelf and say, 'Here, now you're trained,' " Merry said. "What really seems to work is when you make it relevant to each workplace." The person doing the training needs to do a lot of homework, she added, to make it relevant to the people he or she is talking to.
It is crucial that each hearing protector fit the worker and fit the job, Merry said. "There are little quirks to these devices, and people need to be taught how to fit them," she said. Merry suggested training one worker in each facility to fit everyone else there.
Buying a hearing protector is like buying a pair of shoes, Stephenson said. "Like shoes," he said, "you can't assume the right size will fit. Even if it fits, you can't assume it will be comfortable over an eight-hour day." Moreover, one hearing protector is not going to be suitable for every work environment; so if a worker moves about, he or she may need to have several.
It is important that the worker be given precisely the right amount of hearing protection for each type of noise exposure, he stressed. While the problem of underprotection is obvious, workers equipped with hearing protection devices that are too strong for the job are more likely to take them off when they need to converse. Moreover, hearing protection that is too strong creates a potential hazard, as it makes audible warning devices less effective.
Intermittent use of hearing protectors is another reason why hearing conservation programs may not be working, according to Stephenson. "If you buy ear plugs with a noise reduction of 30 dB," he said, "the effective protection is cut in half if you remove them intermittently for as little as 30 minutes in an eight-hour day."
Fortunately, there is a variety of hearing protection devices available on the market -- there are more than 200 styles of ear plugs, according to Merry -- so it is possible to find the right "fit" between each worker and each job.
Even a program with the right hearing protection will not be effective unless there is follow-up to ensure the workers are using the devices, according to Elliott Berger, senior scientist of auditory research at Aearo, a manufacturer of hearing protection devices based in Indianapolis. "Often, people think that if you just do hearing tests and hand out hearing protection, you'll have an effective program," Berger said. "It just doesn't work that way. You need ... engineering controls, education, motivation, supervision and enforcement."
Relying too heavily on hearing protection is one of the most common mistakes companies make in dealing with noise, said Liberty Mutual's Stevenson. Although upfront costs of buying earplugs may seem small, an effective program requires lots of attention and strong administration.
As a result, he said, "Sometimes you find that engineering controls can be more cost-effective than the hearing program." It may take one or two years to get the money back, but if a company can reduce noise exposure to below 85 dB, there is no need for a hearingprogram.
Hank Lick, manager of industrial hygiene at Ford Motor Co., also prefers to engineer sound out of the workplace, where possible. "The best thing that we've done at Ford [in hearing conservation] is to institute a very strict 'buy quiet' regimen," he said. "With that, we've been able to reduce noise levels ... significantly."
For the buy-quiet approach to work, Lick says, "You've got to have the leverage." John Erdreich, an acoustical consultant and a principal at Ostergaard Acoustical Associates, West Orange, N.J., agreed that a lot of suppliers will not invest in building a quieter machine unless they are pressured.
Erdreich, who is president of the National Council of Acoustical Consultants, added that there are other ways to reduce workers' exposure to noise. He said that, when acoustical consultants are called in to solve noise problems at a facility, there are three things they can do: treat the source, treat the path by which the sound is transmitted or treat the receiver. Sometimes, the machine can be quieted; sometimes, placing a barrier around the machine can interrupt the path. Acoustical consultants can help companies determine the most cost-effective approach for reducing noise exposures.
Anytime a company is considering building a plant or expanding a facility, Erdreich said, it would be foolish not to consider noise issues. "It's a lot easier to redesign with a pencil and paper than with a jack hammer and a cement truck," he said.