Hazardous noise is not a new problem in the workplace, so there are many attitudes and habits that are entrenched among exposed workers. In their comprehensive study prepared in 2002, the UK Institute of Occupational Medicine studied the human factor in hearing protection — worker attitudes, risk perception and behavior.1 Their findings confirm many beliefs about workers' attitudes toward hearing conservation, but also uncovered a few unexpected results. Most importantly, the study offers a host of recommendations on how to change existing attitudes and behavior of noise-exposed workers.
The UK researchers surveyed 280 workers at 18 companies across several industries. The study included a variety of large, medium and small employers. In addition to the survey of noise-exposed workers, a separate survey was administered to the managers at those companies to compare responses with the workers. This comparison tells us if workers perceive the hearing conservation programmed the same way it is perceived by the managers.
In the second phase of the study, four companies were selected for intervention actions. Training programs in hearing conservation, tailored to the needs of the work force, were presented at these four companies, and the post-intervention results were evaluated 8 weeks after the training to determine if behavioral changes could be measured. After implementing many of these recommendations at four companies, the researchers found a measurable 70 percent improvement in observed use of hearing protectors.
WHAT RESEARCHERS FOUND
Workers in these 18 companies demonstrated good knowledge in the basic hazards of noise (recognizing that loud noise damages hearing permanently). Only 10 of the 280 respondents could identify the regulatory limit of hazardous noise (85 dBA), nor did workers know that a noise level of 93 dBA is twice as loud as 90 dBA.
Two-thirds of the workers recognized that their company had a hearing conservation program, and this was far more likely to be true in the larger companies (85 percent of workers in large companies). Even though their workplace did have an ongoing program, 24 percent of workers were unaware of its existence.
Among employers with noisy worksites, the biggest misunderstanding about noise was the concept of time-weighted average exposures. Rather than calculate the average 8-hour or 10-hour exposures in a noisy shop, many employers simply designated all areas in their facility with occasional peaks over 85 dBA as being noise-hazardous. This means certain areas were inaccurately designated as noise-hazardous, since average noise levels were below the 85 dB limit. Such overprotection can lead to a mistrust of the program when workers are required to wear hearing protection in areas that usually are not noise-hazardous.
There was one unsettling trend related to the size of noisy companies. Large companies rightly tended to use engineering and administrative controls to reduce noise exposures, and relied upon PPE only after pursuing those other controls first. Small companies, on the other hand, showed a heavy over-reliance upon PPE, perhaps because they lack the understanding of regulations and the hierarchy of controls, and had no trained staff to recommend engineering controls. Compared to their larger counterparts, small employers relied upon word of mouth for knowledge about regulations.
There also was a disturbing disparity when the survey responses of managers were compared to the responses of their noise-exposed workers. At many worksites where employers provided hearing conservation training, workers had little recollection of the training or denied ever receiving it:
When hearing conservation training was provided at new-hire induction, only 27 percent of workers recognized they had been trained.
When hearing conservation training had been provided by posters, only 46 percent of workers recalled receiving the information. When training materials were in the form of a leaflet, only 39 percent recalled receiving training.
Overall, at worksites where managers reportedly provided training in the use of hearing protectors, about two-thirds of the workers could not recall or recognize having been trained. Only one out of five workers recalled receiving training on factors that limit the effectiveness of hearing protectors, even though all their managers reported providing that training.
There is one standout aspect of hearing conservation that was very memorable for workers: the audiometric test. Fully 83 percent of workers at companies administering hearing tests reported receiving the test. Many employers find that the most effective time for administering hearing conservation training is in conjunction with the annual audiometric testing, when the worker is tuned into his personal safety and health.
Use of hearing protectors predictably was variable in the 18 worksites surveyed, with usage rates ranging from 10 percent to 100 percent. As in other studies, the most common reasons cited for inconsistent use of hearing protectors were comfort and communication. Usage rates were particularly poor where managers arbitrarily designated the noise-hazardous areas (poorly defined areas or all-inclusive areas of required hearing protector use that were unwarranted). In such conditions, workers found ample cause to “cheat” on their use of hearing protection — even when it occasionally was warranted.
But the study also found a number of factors that correlated to high usage of hearing protection. Workers were more likely to use hearing protectors consistently in the following conditions:
- If they understand the physiological effects of noise exposure
- Where noise levels are highest
- Where noise levels are constant
- Where the job or task is routine
- Where management demonstrated commitment to hearing conservation
- Where there is positive support from peer groups.
The workers who had a high knowledge with regard to noise levels and hearing conservation also demonstrated high-risk perception (awareness that hazardous workplace noise damages hearing permanently). This in turn correlated with higher usage rates of hearing protection. Among workers whose surveys indicated high-risk perception, 60 percent wore hearing protectors consistently, while only 3 percent never wore protection. Knowledge equals power, some might say, and based upon the results of this study, knowledge equals protection.
Recommendations for effective hearing protector usage include the following:
- Ensure sufficient stock of suitable hearing protectors is available. Utilize earplug dispensers where feasible.
- Where possible, create a strong link between hearing protectors and a specific routine task (usage rates were highest for jobs where routine behavior was required, and where noise levels were constant and unchanging). Try to integrate hearing protection into the standard operating procedures of noisy equipment.
- Make certain supervisors consistently use the hearing protectors, even if their short walk-through exposures in a noisy area do not fully require their use on a time-weighted basis. Employees will view any departure from the required protection, even by supervisors and visitors, as an invitation for them to do likewise.
In the second phase of their study, researchers provided hearing conservation training at four selected facilities. The content and delivery method of the training was tailored to the location. Follow-up evaluations 8 weeks post-training evaluated whether the behavioral changes were long-term.
Effectiveness of hearing conservation training could be measured by two factors: content and method. In terms of content, the most effective training included audio demonstrations of noise-induced hearing loss, actual examples of hazardous noise sources at work, hands-on opportunities for workers to try different types of hearing protectors and demonstrations of proper fit. The least effective training content included detailed explanations of the physics of sound, and detailed explanations of noise regulations.
In terms of training method, the most effective training was formal personal training, supplemented with audio and visual resources. Where companies relied heavily upon informal training, written materials or posters, the low impact of the training was evident: workers often could not recall the content, and personal protective behavior was lowest. Among the companies that provided leaflets to disseminate training, only about one-third of the workers recalled receiving such training. Recommendations for effective training include the following:
- Use audio demonstrations of impaired hearing to show workers the risk of hazardous noise. Written information is a useful supplement, but is ineffective when used on its own.
- Employers cannot rely on the published instructions for fitting hearing protectors, provided on the packaging, as the primary source of information for effective hearing conservation. Instead, training must be engaging, relevant and meaningful to the employees.
- Utilize testimonials from peers with existing hearing loss to talk about their loss and its effects on personal and social life, and to encourage ongoing use of hearing protectors.
- Seek feedback and evaluate the effectiveness of the training to determine the content and delivery methods that are most meaningful in changing behavior toward better hearing.
Can personal attitudes toward hearing protection and workplace behavior be changed by knowledge and training? The answer is a resounding “yes” in this extensive study. In most worksites, the observed use of hearing protection measurably increased after effective training interventions, delivering useful information in engaging formats.
Brad Witt is the director of hearing conservation at Howard Leight / Sperian Hearing Protection in San Diego, where he manages the acoustical laboratory and provides training to professional groups in all aspects of hearing conservation. He can be reached at 619-619-1412 or [email protected].
1G.W. Hughson, R.E. Mulholland, H.A. Cowie, “Behavioural Studies of People's Attitudes to Wearing Hearing Protection and How These Might Be Changed.” Research report 028 of the Institute of Occupational Medicine (2002), Edinburgh, UK.