As a retired Army audiologist, Richard W. Danielson, PhD, manager of audiology and hearing conservation at NASA's Johnson Space Center in Houston, does things by the book, and enforcing rules to protect the troops against noise-induced hearing loss is no exception.
“In the military, a range safety officer can tell a drill sergeant or a colonel, ‘We're going to shut this range down if you don't have hearing protection available for your soldiers, plain and simple’” Danielson says.
However, convincing members of his own family to safeguard their hearing when using noisy machinery—even chainsaws—was an uphill battle. “I'm from a farming family,” he says, “so it was very frustrating for me to come back home and find such resistance to hearing protection and to hear them bluntly say, ‘Oh, it's okay; this noise won't hurt me.’”
Noise-induced hearing loss remains a huge public health problem, affecting as many as 30 million Americans, according to the National Institute for Occupational Safety and Health (NIOSH). Studies show that people are not informed about the risks they face in everyday life. In one NIOSH survey, nearly a third of adults said that although they regularly use noisy equipment, such as lawnmowers and vacuum cleaners, they don't believe that using these machines will damage their hearing.
Even in regulated environments, people often fail to take appropriate measures. A NIOSH study published in 2002 found that only 41% of industrial workers exposed to hazardous noise levels wore hearing protection. In mining, where noise remains a significant problem, about 90% of coal miners have a hearing impairment by age 50.
Yet, hearing health experts say noise-induced hearing loss is preventable if precautions are taken to avoid prolonged and excessive noise exposure. Getting that message out to the general public, especially children, is a central theme of recent hearing loss prevention campaigns. At the same time, governmental organizations, including the military, the U.S. Department of Veterans Affairs, and NIOSH, are conducting research and sponsoring programs to prevent hearing loss before it occurs.
PREVENTION BEFORE CONSERVATION
While the terms “hearing conservation” and “hearing loss prevention” are often used interchangeably, there's a subtle but important distinction, reflecting the evolution of the hearing conservation field.
“Hearing conservation comes from the early 1980s, when the first Occupational Safety and Health Administration [OSHA] programs were coming online to deal with noise-induced hearing loss,” says Deanne Meinke, PhD, assistant professor of audiology and speech-language sciences at the University of Northern Colorado in Greeley and president of the National Hearing Conservation Association (NHCA), a multidisciplinary group of professionals dedicated to hearing loss prevention. “I think the view then was we had to conserve what they had left,” she says.
Figure. Deanne Meink...Image Tools
But with advances in science and technology, greater emphasis is being placed on preventing hearing loss before it occurs. That shift, from conservation to prevention, is reflected in NIOSH's recommendations for occupational noise exposure, published in 1972 and updated in 1998. The earlier document provided guidelines for establishing a comprehensive “hearing conservation program,” while the newer version lays out criteria for managing “hearing loss prevention” programs. “So that's where that terminology really took hold and people have tried to embrace it,” Meinke explains.
Professional organizations jumped aboard the prevention bandwagon soon after.
In October 2002, the board of directors of the American Council of Occupational and Environmental Medicine issued a position statement recognizing the role of prevention. “ACOEM believes that occupational clinicians need to become increasingly proficient in the early detection and prevention of noise-induced hearing loss,” it states. “This requires clarification of current best practices, as well as additional research into certain aspects of noise-induced hearing loss that remain poorly understood.”
In March 2003, the American Speech-Language-Hearing Association (ASHA) adopted a new position statement recognizing audiologists' role in “the prevention of significant, permanent hearing loss resulting from on- and off-the-job exposure to ototraumatic agents (most commonly noise).”
Later that year, the American Academy of Audiology (AAA) issued a statement on preventing noise-induced occupational hearing loss, asserting, “No one needs to lose his or her hearing in order to earn a living.” The statement outlines best practices and, in closing, notes that the academy “supports audiologists leading the efforts to prevent occupational hearing loss through comprehensive hearing loss prevention programs.”
AAA's 2007 Annual Convention also highlighted the topic with the intent of educating audiologists “who might not consider themselves occupational audiologists,” says Danielson, the organizer of that strand of the conference.
He adds, “We maintain that if folks are dispensing hearing aids and finding that there's been a change in hearing so they need to reprogram the hearing aid to be more powerful, or if they're working with ENT patients who are in for another purpose, it just seems so logical to ask a couple of questions about their occupational or non-occupational noise exposures, and then be knowledgeable about some strategies that people can take to prevent hearing loss.”
Figure. Richard Dani...Image Tools
REACHING THEM EARLY
One-on-one contact between patient and practitioner can be extremely beneficial, hearing health experts agree. (See the sidebar, “Any clinician can help prevent loss.”) However, there is also growing recognition that the education process must begin much earlier.
That's the mission of Dangerous Decibels, a public health campaign aimed at school-aged children. The project has several components, including a museum exhibit at the Oregon Museum of Science and Industry in Portland, a “virtual” online exhibit that includes computer games, and classroom programs primarily targeting kids in kindergarten through eighth grade. In addition, the Oregon Health and Science University hosts training workshops to prepare instructors to present the Dangerous Decibels program to kids in the classroom. The course offers information on hearing, anatomy, the physics of sound, the sources and effects of dangerous sounds, and how to protect hearing.
One of the partners in the project is William H. (Billy) Martin, PhD, professor of otolaryngology/head and neck surgery and public health & preventive medicine at Oregon Health and Science University. He says, “We want people to have an intuitive knowledge of what sounds are dangerous, what the consequences of being exposed to those sounds are, and how to protect themselves so they apply them on their own in every situation. So, when they're in the workplace, their natural tendency is going to be to demand hearing protection.”
While Dangerous Decibels started in Portland, it's already garnering international interest. Hearing aid manufacturer Widex Canada Ltd. recently had 15 employees attend a training program. Eight of them completed it, making them eligible to present the material in Canadian classrooms. Officials in New Zealand recently committed to providing the program in classrooms throughout the country.
But does it work? Initial research by Martin and colleagues Susan E. Griest, MPH, and Robert L. Folmer, PhD, of the Oregon Hearing Research Center at OHSU suggests that the earlier kids are exposed to prevention messages, the better.
Their study involved 478 fourth-graders and 550 seventh-graders. Roughly half of each group participated in the program and filled out questionnaires afterwards. The other students received no instruction in hearing loss prevention. Three months later, all of them completed follow-up questionnaires. Among program participants, knowledge and attitudes about hearing loss improved. Fourth graders maintained those improvements even 3 months later, but seventh graders did not.
“By seventh grade, after 3 years, they're not forgetting the information, but their willingness to comply drops dramatically,” Martin notes.
Next, the researchers would like to conduct a 9-year longitudinal study with hearing education beginning in first grade and repeated in fourth and seventh grades. While it's difficult to secure funding for such a long-term study, Martin believes it is necessary. “The challenge with hearing health education is that there are a lot of programs that are designed by well-intentioned, good-meaning people, but they've never been through any kind of summative evaluation to find out if they really work,” he says.
Figure. Billy Martin...Image Tools
Dangerous Decibels is “probably one of the most well-developed programs with research that supports the effort,” claims Meinke, who chairs NHCA's Task Force on Children and Noise, “but there's certainly lots to be done in this area.”
The National Institute on Deafness and Other Communications Disorders (NIDCD), for one, is seeking to fill the gap by refocusing its 10-year-old “Wise Ears” campaign. The new initiative, set to launch in October, will specifically target “tweens” ages 8 to 12 and their parents to encourage healthy hearing habits, according to Patricia Blessing, chief of NIDCD's Office of Health Communication and Public Liaison. NIDCD wants parents and kids to understand the sources of noise, from rock concerts to NASCAR races; the danger that noise poses; and how to protect their hearing, she says.
PREVENTION AT WORK
Hearing loss prevention isn't just kids' stuff. Researchers at NIOSH are tackling workplace prevention from every angle, beginning with a greater push to gather data on the incidence and prevalence of work-related hearing loss and the occurrence of hazardous noise exposure in occupational settings.
Other goals of the institute's 2007-2016 research agenda are: to reduce noise through engineering controls, to improve the use and effectiveness of personal protection devices, to establish evidence-based best practices for hearing loss prevention programs, and to identify hearing loss risk factors, such as individual susceptibility to noise and exposure to ototoxins.
“Prevention through Design”
In the area of engineering controls, for example, NIOSH is leading a “Prevention through Design” initiative using input from every industrial sector to “design out” occupational hazards. In mining, one objective is to quiet the continuous mining machines used to extract coal. “We have already developed a control that has been tested in the lab and proven underground to be durable and also provide attenuation,” says R.J. Matetic, PhD, chief of the Hearing Loss Prevention Branch at NIOSH's Pittsburgh Research Laboratory. That fix will reduce noise levels by 7 dB, he says.
Simply ensuring that workers get the proper amount of noise attenuation on the job also remains a challenge.
“Right now, there's no requirement for fit testing for workers with hearing protectors,” observes Mark R. Stephenson, PhD, senior research audiologist and coordinator of NIOSH Hearing Loss Research in Cincinnati. To fill the gap, NIOSH is involved in the development of a fit-testing procedure that will work with any hearing protector and will tie into an employer's audiometric database, he says. Field-testing will begin in the next year or so.
What's more, NIOSH is using health communications theory to develop training materials for workers on the use and proper fit of their hearing protectors. Just as women make it a habit to get annual mammograms and motorists instinctively buckle up, NIOSH wants to empower workers to adopt behaviors to protect their hearing. “Words have impact and how you communicate the training message has a real impact,” Stephenson notes.
A study in the May 2008 Journal of Applied Communication Research examines one model of designing messages to motivate behavior to prevent hearing loss. For the study, researchers created two brochures, one for farmers and one for landscapers. Each brochure used the “extended parallel processing model,” a method of persuasion that highlights a potential threat and a simple response. In this case, the brochures described the effects of hearing loss and recommended earplugs or earmuffs to save their hearing.
The study, led by Sandi W. Smith, PhD, a professor in communication at Michigan State University in East Lansing, found that landscapers exposed to the material rated the threat of hearing loss and the efficacy of using hearing protection more highly than a control group. In addition, their intent to use hearing protection was higher. It was a different story for farmers. Compared with the control group, farmers exposed to the brochure had no greater perception of threat or efficacy, although their intent to use hearing protection was higher.
The researchers suspect that the brochure acted as a stimulus, motivating farmers to protect their hearing. “Practitioners can take away from this finding the reminder that they must strive to keep a continuing stream of persuasive materials in front of their target populations,” Smith and colleagues write. “Even when threat and efficacy are high, stimulus materials that might serve as positive cues to action are needed on a regular basis.”
Safe in Sound awards
To help identify and promote best practices, NIOSH partnered with NHCA to create Safe in Sound (www.safeinsound.us), a new award recognizing excellence in hearing loss prevention in the work environment. An award will be given in each of three sectors—construction, manufacturing, and service—and a fourth award will recognize innovation by an individual or business in any sector. Applications are due September 1, and the awards will be given at NHCAs annual meeting in February 2009.
Earlier this year, NIOSH, OSHA, and NHCA signed an agreement to collaborate on efforts to prevent work-related hearing loss. The three organizations will use their collective expertise to “advance a culture of good hearing health” by helping to develop hearing conservation and hearing loss prevention programs and sharing best practices and technical knowledge.
Hearing protection manufacturers are responding to the prevention challenge, too. One way is through the use of color and design to appeal to younger workers.
“With any personal protective equipment, and hearing protection is certainly right up there, the problem is getting people motivated to want to use it,” says Elliott H. Berger, MS, INCE, senior scientist in audiology research at E-A-R/Aearo Technologies in Indianapolis. “So if they think it's uncool or unsightly, they're less likely to use it.”
Aearo, for example, sells a product called Tattoo that features barbed-wire images around the back of an earplug. “It is targeted for a younger, edgy generation that embraces body adornments and piercings,” Berger explains.
There are compelling reasons to teach adult workers, members of the armed forces, and veterans about preventing hearing loss. Quality of life, of course, is one. Money is another. From an occupational point of view, the sting of workers' compensation costs is helping spur interest in prevention. Nationally, occupational hearing loss costs an estimated $242.4 million annually in disability alone, NIOSH reports.
“Employers really look toward hearing loss prevention programs as a way to impact those long-term costs,” Meinke says.
For its part, the Department of Veterans Affairs (VA) paid out $1.2 billion in compensation to veterans in fiscal year '06 for service-related hearing loss and tinnitus, says Stephen Fausti, PhD, director of the National Center for Rehabilitative Auditory Research (NCRAR) in Portland, OR. “So prevention has some very profound economic issues associated with it,” he says, but adds, “You also have to think about quality of life in later years.”
Figure. Stephen Faus...Image Tools
With that in mind, the NCRAR is collaborating with the U.S. Army on a multimedia educational program to be piloted at two military installations and the Portland VA Medical Center. Soldiers and veterans will access computer modules that provide information about hearing, the damage that noise can inflict upon the auditory system, and the importance of hearing protection. Participants will experience what it's like to have hearing loss and tinnitus via computer simulation and they'll self-administer a screening examination to test their own hearing.
By boosting education and, in turn, compliance, NCRAR hopes to reduce the incidence of tinnitus, muffled hearing, and difficulty hearing in backgrounds of noise. If the pilot proves successful, the goal would be to expand it nationally. “We want to get the message out that people need to protect their hearing whether or not they have damaged hearing,” Fausti says.
HOW CLINICIANS CAN HELP PREVENT LOSS
You don't have to be a hearing conservationist to participate in hearing loss prevention. “The average clinician is going to play a very important role,” says Mark R. Stephenson, PhD, senior research audiologist and coordinator of hearing loss research at NIOSH. “People are going to come to them because they have a hearing loss, and they will be the people to identify that occupational hearing loss and recommend interventions.”
Adding a prevention component to the mix of diagnostic and rehabilitative services you already offer is pretty simple, hearing loss experts said. Here's their advice:
Raise the issue. Ask patients if they are exposed to noise at work, at home, or in their recreational activities. You might ask, “Do you use a gas-powered mower?” or “Do you ever go hunting?” It can be that simple “just to get it on these people's radar screen that this can be dangerous,” said William H. (Billy) Martin, PhD, professor of otolaryngology/head and neck surgery and public health and preventive medicine at Oregon Health and Science University.
Teach a class. Before selling his practice, Dennis L. Burrows, PhD, now a consultant in business and practice management in Kalamazoo, MI, taught fourth- through eighth-grade classes about the dangers of excessive volume on personal listening devices and how to protect their hearing. He drew information from ASHA's public education campaign, “America: Tuned In Today…But Tuned Out Tomorrow?” better known as “Listen To Your Buds.” Locally, at least, the message seemed to sink in. When surveyed 3 months and a year later, says Burrows, “a significant portion of the kids had in fact said that they were turning their volume down and were being careful about their hearing.”
Provide resources. You can help patients learn about preventing hearing loss by directing them to relevant web sites and offering brochures on the topic. The House Ear Institute's teen outreach campaign, “It's How You Listen That Counts,” at www.earbud.org; features a hearing simulator that mimics hearing changes due to general aging, noise-induced damage, and tinnitus. There's valuable information in the Hearing Loss Prevention section of the Better Hearing Institute site (www.betterhearing.org), including tips from Richard Danielson, PhD, on how to prevent noise-induced hearing loss. The National Institute on Deafness and Other Communication Disorders (NIDCD) offers information on noise-induced hearing loss at www.nidcd.nih.gov/health/hearing/noise.
© 2008 Lippincott Williams & Wilkins, Inc.