Dr. Laurie Wells, Doctor of Audiology
3M | www.3M.com/CHC
Manufacturing and construction sites are typically noisy places. Prolonged exposure to loud, aggravating, and excessive sounds can have harmful effects on worker health. However, symptoms are not always immediate or obvious because noise-induced hearing loss typically happens gradually. Over time, excessive noise exposure may damage the tiny hair cells in the inner ear and lead to tinnitus (ringing of the ears), or partial or permanent hearing loss.
According to the Occupational Safety and Health Administration (OSHA), employers are required to provide a “continuing, effective hearing conservation program” for employees who are exposed to potentially hazardous noise. To protect workers from hearing loss, “hearing conservation programs” (HCP) that aim to reduce noise, and check and promote hearing protection, are an important part of a workplace safety plan.
Here are seven elements to a comprehensive HCP.
1. Measure. Noise measurement forms the foundation of a good HCP. Only by monitoring noise in different areas of a manufacturing facility or construction site, and conducting noise surveys on different processes, tasks, and tools can an employer collect the data necessary to identify hazardous sounds and determine control measures.
Noise surveys can be simple or complex, conducted by in-house safety teams or consultants, and ideally should include devices that accurately measure occupational and environmental safety hazards for tracking and evaluation over time. At the very least, a general-purpose meter (Type 2 microphone) and specific instrument settings are needed for occupational sound surveys. Sound level meters measure sound pressure levels in real time and dosimeters integrate noise levels over time to calculate a worker’s noise exposure.
In the U.S., OSHA requires employers to maintain an active hearing conservation program whenever employees have an eight-hour, time-weighted-average to noise of 85 dBA or more. Personal monitoring of noise exposure of an individual worker is needed when workers are highly mobile and noise levels vary considerably.
A few indications that noise may be a problem in your workplace include:
- Employees hear ringing or humming in their ears after exposure to loud sounds
- Some workers notice temporary loss of hearing ability when leaving work
- It is often necessary to shout to be heard by a coworker only an arm’s length away
2. Control. Certain operations and machinery create high noise levels. But do they have to? “Buy Quiet” is a type of prevention-by-design approach that reduces workplace noise hazards by specifying machinery, tools, or processes that create less noise. This is best accomplished when implementing a new production process or replacing older equipment.
Buy Quiet is one approach to controlling workplace noise when feasible. Applying “engineering controls” is another approach that aims to modify a facility’s current equipment or workplace environment in some way so that less sound energy is created or transmitted to workers. It falls in line with the concept of Hierarchy of Controls, which is well established in occupational health and safety. Simply put, Hierarchy of Controls states that it is more effective to eliminate or decrease the severity of the hazard than to change the way people work or require employees to wear protective equipment.
One tip to bear in mind when engineering controls is to prioritize what noise-control projects will be most effective. While it may seem logical to focus attention on the highest noise source in a facility, it is often possible to achieve a more significant decrease in noise exposure by first controlling sounds in the areas closest to where employees spend most of their time.
“Administrative controls” are another approach to noise control and aim to limit the time workers spend in high-noise areas. These policies are often necessary when engineering controls are not feasible or cost effective.
3. Protect. In an occupational hearing conservation program, it is preferable to eliminate or decrease the severity of a hazard rather than change the way people work. However, when controlling hazardous noise is not possible or feasible, hearing protectors are essential.
To work effectively, hearing protectors must be comfortable, compatible with other personal protection equipment, fit properly, and provide adequate protection for the environment. A job may require several types of hearing protectors to balance the need for noise reduction with those needs of a worker and work environment. For example, hearing protection should not impede a worker’s ability to communicate or hear important sounds and safety instructions at a job site.
Conducting individual fit testing of earplugs and earmuffs can help ensure worker compliance and proper use. Also bear in mind that people like options. When personal preferences and worker choices are permitted during PPE selection, employees are typically more satisfied and invested in the outcome — meaning they’re more likely to want to wear the safety gear.
4. Check. An audiometric testing program checks the hearing thresholds of workers and tracks them over time. The objective is to detect changes or shifts in hearing that may signal the beginning stages of noise-induced hearing loss. Ideally, a baseline hearing check (audiogram) is done prior to a worker’s first exposure to hazardous noise, and then compared to future, routine hearing checks —typically, once a year.
Early identification of a worker’s hearing loss lets employers intervene before symptoms get worse. Plus, the testing process provides an opportunity to remind and teach workers about the importance of their own hearing health and status. An audiometric database can also offer a snapshot of the hearing health of the noise-exposed workforce and be used to identify trends and develop intervention plans.
5. Train. Noise-induced hearing loss typically happens gradually, so it is important to educate workers on the effects of exposure to loud noise and on proper use of hearing protection. One of the keys to successful training is to incorporate active learning. People typically retain more information when they are actively involved in their learning.
Employers may improve the success of their hearing loss prevention efforts by strengthening worker training programs to address the knowledge of the people involved along with their attitudes and behaviors.
It is good practice to schedule employee training at times and locations that will accommodate work and production schedules, and when employees are most likely to be attentive, alert, and focused. People who are tired, distracted, or overwhelmed are less likely to learn new ideas or behaviors.
A few reasons to train include:
- Consistent and proper use of hearing protectors is likely to increase among employees who become personally committed to protecting themselves from noise at work and elsewhere.
- Employee satisfaction may improve when they understand how noise exposures are measured and the steps being taken by the employer to control noise.
- Better recognition of situations when hearing protectors or noise controls are inadequate may be possible once employees learn to identify the warning signs of hearing loss and damage.
- Documenting the results of training helps employers demonstrate compliance with regulations that require employers to provide employee training as part of an occupational HCP.
6. Record. Accurate and complete record keeping is often more than a legal requirement; it’s good business. Good records may provide evidence to help an employer accurately track employees’ hearing over time and, if necessary, record cases of work-related noise-induced hearing loss on the OSHA log of illness and injury, and respond to worker compensation claims.
For general industry, OSHA (Regulation 29 CFR 1910.95: Occupational Noise Exposure) requires employers to keep an accurate record of noise exposure measurements for two years, and audiometric test records for the duration of employment of the employees who are in a hearing conservation program. Because records in hearing conservation programs may include confidential health information, strong data protection is recommended to ensure the privacy of individual workers and assure that only those who have the proper credentials have access to sensitive information.
7. Evaluate. The goal of a hearing conservation program is to protect workers from developing hearing loss or problems caused by work-related hazardous noise, so it is important to plan for adequate checks and balances and ask: Is the program actually preventing noise-induced hearing loss? How can it be improved? Is the HCP efficient and cost effective?
Regular program evaluation can identify trends, detect gaps, and drive improvements. Routine evaluations of the program are critical, and there are several ways to measure effectiveness. One way is to evaluate changes that occur as a result of the program, such as the number of hearing loss cases or a reduction in the occurrence of noise sources or exposures (because of implementation of quieter equipment, for example). Another approach considers the costs of delivering the program and comparing those to the costs of implementing noise controls.
It can also be helpful to audit the HCP for compliance (of what occurs and what’s only on paper). A recent hearing conservation program checklist to assess effectiveness is at https://tinyurl.com/protect-hearing
It is also important to evaluate a program through the people it intends to keep safe and healthy, so it is a good practice to ensure that assessments include employee reviews.