Four key elements of follow-up after the occupational audiogram that can bring real value to the employer—and preventive education to the noise-exposed worker.
The last tone of the audiometric test has been presented, and the patient waits silently in the booth for the hearing care professional to open the door. What happens next? If the patient is a noise-exposed worker in an occupational Hearing Conservation Program, the answer to what happens next can be quite different from that for other patients in the audiometric booth.
Below are four key elements of follow-up after the occupational audiogram has been completed that can bring real value to the employer, and preventive education to the noise-exposed worker. These best practices define whether the audiometric testing will serve simply as a hearing loss documentation program, or a hearing loss prevention program. In an OSHA-standard Hearing Conservation Program, the real work (and benefit) of the audiometric testing begins immediately after that booth door is opened.
|Brad Witt, MA, is director of hearing conservation at Sperian Safety Group, Smithfield, RI. He is past president of the National Hearing Conservation Association (NHCA) and managed a hearing conservation practice for 14 years.|
#1 Provide Immediate Feedback
Research has confirmed the value of immediate feedback in occupational audiometric testing.1 At a large utility company, one group of workers was given their audiometric results immediately following testing, while another group of workers received no feedback. Over 3 years, the rates of significant shift in hearing were twice as high in the group that received no feedback, even though noise exposures were similar in both groups.
After sitting in a quiet sound booth for several minutes, most workers are anxious to immediately know simple answers to three personal questions:
- What is the current status of my hearing?
- How does my hearing now compare to previous tests?
- Is any action required on my part?
Feedback that immediately answers these three questions following the audiometric test is most influential for making noise-exposed workers active players in their own hearing conservation.
#2 Provide One-on-one Training
There is no better time for hearing conservation training than immediately following the audiogram; the worker is focused on hearing, anxious to know results, and compliant in changing behavior. Companies that delay this individual hearing conservation training to a group session drop one of their most powerful tools against noise-induced hearing loss.
That training can be a simple 2-minute demonstration of proper earplug fitting. In a study of 192 noise-exposed workers at a steel mill, employees who received a 2-minute personal tutorial on how to properly insert the earplugs achieved on average 14 dB more protection from their earplugs than prior to instruction.2
|FIGURE 1. The Roll/Pull/Hold mnemonic is illustrated in a NIOSH Web site that includes graphics as well as a downloadable video you can use in your own training program.|
What information is most useful for noise-exposed workers to know? Two items are critical: how to recognize hazardous noise, and how to properly fit hearing protectors. Since the damaging effects of noise occur at decibel levels far below painful levels, it is critical to teach the noise-exposed worker how to recognize noise damage. Hazardous noise of 85 dB (whether on-the-job or off-the-job) can be estimated fairly accurately with this simple rule of thumb: if you must shout to be understood by someone just an arm’s length away, then that background noise is most likely hazardous.
In the fitting of formable earplugs, teach the worker a simple three-step process: Roll, Pull, Hold. Roll down a foam earplug into a small crease-free cylinder, pull the outer ear up and back to open the ear canal, insert the earplug and hold in place while it expands. The earplug should be inserted far enough that it cannot be seen protruding from the outer ear when you look at yourself in the mirror. The Roll/Pull/Hold mnemonic is illustrated in a NIOSH Web site3 that includes graphics, as well as a downloadable video you can use in your own training program (Figure 1). Free fitting posters are also available from a variety of sources, showing the “Dos and Don’ts” of fitting earplugs and earmuffs.4
Numerous research studies point out the advantage of individual one-on-one training over group training. In a study of 100 noise-exposed workers at eight different facilities, the fit of hearing protectors was measured, and then compared to many different factors from the worker’s profile to see which factor could best predict a proper earplug fit for a particular worker. Only one factor was a good predictor: whether that worker had received individual one-on-one training in fitting earplugs (Figure 2). No other factors correlated well (including the number of group training sessions presented to the workers).5
As part of a comprehensive study prepared in 2002, the Institute of Occupational Medicine in the United Kingdom studied the human factor in hearing protection—worker attitudes, risk perception, and behavior.6 As with other studies, they found the best training method to be formal personal training, supplemented with audio and visual resources. Where companies relied heavily upon informal training, group training, pamphlets, or posters, the low impact of the training was evident: workers often could not recall the content, and personal protective behavior was lowest. But when noise-exposed workers underwent formal personal training that included audiovisual resources (audio demonstrations of hearing loss, for example), the researchers found a 70% improvement in observed use of hearing protectors.
|FIGURE 2. Results from a study of 100 noise-exposed workers at eight different facilities. The fit of hearing protectors was measured, and then compared to many different factors from the worker’s profile to see which factor could best predict a proper earplug fit for a particular worker. Only one factor was a good predictor: whether that worker had received individual one-on-one training in fitting earplugs. No other factors correlated well (including the number of group training sessions presented to the workers). Data from the Howard Leight Acoustical Laboratory, San Diego.|
#3 Analyze the Audiogram for Work-Related Shifts
|FIGURE 3. Fit testing of hearing protection is now available from several manufacturers. Instead of estimating how much protection a worker obtains, the decibel level of protection can actually be measured to ensure proper fit. New field verification technologies, like VeriPRO™ from Howard Leight, can determine whether employees are achieving ideal fit or attenuation, or require a more appropriate HPD for their application.|
In a best-practices tutorial for clinical audiologists performing follow-up on occupational audiograms,7 industrial audiologist Richard Stepkin outlines the key elements of clinical follow-up:
- Analyze the audiograms for OSHA-defined shifts in hearing, not for compensability.
- If qualified, define whether that shift is “work noise-related.” This is based on an extensive on-job and off-job noise exposure history.
- If “work noise-related hearing loss” is ruled out, testing beyond the basic battery is typically unnecessary.
- Report the findings using terminology that gives the employer definitive answers: Is there a persistent shift in hearing, and is that shift work noise-related?
#4 Recommend Appropriate Follow-up
Most employers know a significant shift in hearing requires follow-up, but what follow-up is most effective? As a hearing professional, your knowledge of current best practices and technological advances in hearing conservation is highly valuable for that employer. Here are three follow-up steps that have proven to be extremely effective in stopping more progression of hearing loss in a noise-exposed worker:
Refit the hearing protectors, and retrain the user individually. This initial step seems so basic that it is hard to imagine companies not doing it. Yet many employers overlook this first step, and continue to simply “retrain” their workers with a shift in hearing by having them watch the perennial “noise video” again.
Progressive companies no longer only show a hearing conservation video in a group setting to provide the OSHA-required annual training. Instead, individual training in hearing protector fit is becoming the preferred method of training. Some companies require that workers must demonstrate that they can properly fit the earplug before they leave the training room. This often takes multiple tries with different earplug models. But obtaining a proper fit of hearing protection is the critical tool for preventing additional shifts in hearing—something that is often lost in group training sessions.
Fit testing of hearing protection is now available from several manufacturers. Instead of estimating how much protection a worker obtains, the decibel level of protection can actually be measured to ensure proper fit (Figure 3).
In a field study using one of these fit measurement systems, 100 workers were tested with the “normal fit” of the earplugs they routinely wore (Figure 4). Earplugs were from a variety of manufacturers, and included single-use foam, pre-molded reusable, and custom-molded earplugs. Nearly one-third of the workers obtained attenuation that was slightly higher than the published Noise Reduction Rating (NRR) for their chosen earplug. The middle third of workers achieved attenuation within 5 dB below the NRR, and the bottom third of workers showed real-world attenuation anywhere from 5 to 30 dB below the NRR.
|FIGURE 4. Scattergram showing field attenuation of 100 workers at eight companies, tested with the VeriPRO™ fit verification system. Nearly two-thirds of the workers achieved attenuation within 5 dB or higher of the published attenuation for their particular earplug. Data from the Howard Leight Acoustical Laboratory, San Diego.|
Use in-ear dosimetry to monitor exposures. The ultimate protection from hazardous noise is now available in a method called in-ear dosimetry. Using microphones inserted on the eardrum-side of an earplug, the in-ear dosimeter constantly monitors real-time noise exposures under the earplug while the worker is on the job, so that a worker and safety manager know exactly how much noise is reaching the eardrum throughout a workday. Using such a system, one facility with a significant number of noise-exposed workers found their company’s progression of noise-induced hearing loss stopped immediately.8
|FIGURE 5. Some companies require that workers must demonstrate that they can properly fit the earplug before they leave the training room. This often takes multiple tries with different earplug models. But obtaining a proper fit of hearing protection is the critical tool for preventing additional shifts in hearing—something that is often lost in group training sessions.|
The audiometric test alone does nothing to protect hearing from hazardous workplace noise. Far too many companies provide testing that simply documents that their Hearing Conservation Program is not working. The audiogram becomes valuable only when it is used proactively to prevent additional hearing loss. By providing immediate feedback to workers, training them individually in fit, analyzing the current audiogram for early shifts, and implementing preventive follow-up actions, the audiogram becomes the powerful tool it was intended to be in preventing noise-induced hearing loss.
- Witt B. Immediate feedback in a Hearing Conservation Program. Paper presented at: Annual meeting of the National Hearing Conservation Association; 1992; Cincinnati.
- Michael K, Bloyer C. Hearing protector measurement on the end user: a case study. Paper presented at: Annual meeting of the National Hearing Conservation Association; February 1993; Albuquerque, NM.
- National Institute for Occupational Safety and Health (NIOSH). How to wear soft foam earplugs. Available at: . Accessed October 20, 2008.
- Howard Leight LLC. Conservation is about caring posters. Available at: www.howard leight.com/bestpractices/commit. Accessed October 20, 2008.
- Witt B. Why are Joe’s earplugs working?. Paper presented at: Annual meeting of the National Hearing Conservation Association; February 2007; Savannah, Ga.
- Hughson GW, Mulholland RE, Cowie HA. Behavioural studies of people’s attitudes to wearing hearing protection and how these might be changed (Research report 028). Edinburgh, UK: Institute of Occupational Medicine; 2002. Available at: www.iom-world.org/research/iomreports.php. Accessed October 20, 2008.
- Stepkin RL. A little occupational audiology for the clinical audiologist. ASHA Leader. June 4, 2005.
- Michael K. Upstream prevention of noise-induced hearing loss: verifying effective use of hearing protection. Paper presented at: Annual meeting of the National Hearing Conservation Association; February 2003; Atlanta.
Correspondence can be addressed to Brad Witt, Sperian Hearing Protection LLC, e-mail: .
Citation for this article:
Witt B. After the occupational audiogram…What Now? The Hearing Review. 2008;15(12):12-16.