No matter the industry, employee safety is a top priority for all employers. While the more obvious safety hazards take the foreground for injury and illness hazard assessments, noise exposure risks may go undetected. Sadly, thousands of workers experience occupational hearing loss or injury every year.
Most noise-induced hearing loss is gradual and permanent, but largely preventable. One of the critical components of a hearing protection program is setting a clear standard for employees. This includes training and vigilant use of personal protective equipment (PPE), especially in high-noise areas.
Hearing loss on the job
Everyone is at risk for hearing loss. Both the frequency and intensity of noise exposure contribute to hearing loss. Walk around your workplace and have a listen. Are your workers shouting to be heard?
Are you yelling at two or three feet away?
Try the Occupational Safety and Health Administration’s (OSHA’s) two- to three-foot rule: Stand an arm’s length away from a coworker. If you have to shout to be heard, the noise level is probably above 85 decibels A-weighted (dBA).
Industries at risk for noise hazards
Some hearing loss is sudden, but most noise-induced hearing loss occurs over years of noise exposure. Any workplace is susceptible to noise hazards, so don’t assume you’re not at risk because your trade isn’t on this list. But here are a few industries and professions that are at higher risk for noise hazards.
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Agriculture
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Air transportation
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Artisans
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Construction
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Engineering
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Laboratories and research
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Landscaping
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Laundry
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Law enforcement and first responders
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Machinery
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Maintenance
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Manufacturing and assembly lines
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Military
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Mining
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Music
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Trucking and transportation
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Warehousing
Some industries might not be what you expected, such as trucking and transportation. Truckers are exposed to continuous road noise from tires on pavement and other mechanical noise that can lead to permanent hearing loss. Even dental offices might pose a risk for certain types of hearing loss due to tools that emit high-frequency noises, which may erode hearing over time. Your focus should be on recognizing and mitigating noise hazards, regardless of the industry you’re in.
Testing noise levels on your own
If noise exposure is a risk, consider testing your environment. You can use results to make informed decisions on how to proceed.
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Download the National Institute for Occupational Safety and Health’s (NIOSH’s) Sound Level Meter App to measure noise levels on your own.
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You can buy a sound level meter device, but you’ll need to know how to calibrate and read it.
Professional testing for noise levels
Getting a professional evaluation lets you rest easy knowing that you’ve invested in the health of your workers. Even if the answer is that you’ve got no noise exposures, it’s money well spent. And if you end up exposing a noise hazard, you’re on your way to proactively reducing the risk.
Before scheduling an appointment, ask the evaluator if they’ll give you recommendations for ways to block or isolate the noise.
Either way, if you have noise exposures, take steps to create a hearing protection program that works for your workers and operations.
OSHA’s hearing conservation standard
OSHA’s hearing conservation standard (standard 1910.95) requires employers to provide hearing protection to workers exposed to noise beyond certain threshold levels.
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OSHA uses a permissible exposure limit (PEL) rating system to determine how long an employee can
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work around noise without hearing protection.
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Hearing protection is based on the PEL rating and source noise decibels.
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According to OSHA standards, exposure to over 85 decibels of noise for more than eight hours per day can result in permanent noise-induced hearing loss.
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Employers must establish a hearing conservation program when noise levels are at or above 85 decibels for an eight-hour workday.
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For every 5 decibels over 90 decibels of noise, the time a worker can be exposed is half. For example, a high-pressure cleaning machine emits 100 decibels. The noise level is 10 decibels over the OSHA PEL of 90 decibels. Without hearing protection, a worker can use the pressure washer for two hours, not eight hours. If the worker uses hearing protection that reduces the noise exposure levels by 10 decibels or more, the worker can safely use the pressure washer for an eight-hour workday.
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Hearing loss is a recordable injury or illness incident if there is a standard threshold shift in a worker’s hearing test results (usually 10 decibels or more of hearing loss).
OSHA lists maximum thresholds for noise levels. Try to reduce noise levels as much as possible, even lower than 85 decibels.
Common noise hazards
Many hazards can cause hearing injuries in the workplace. While these hazards vary by industry, the standard of providing proper PPE ensures workers are safe no matter where they work. Some noise hazards to be considered include:
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Grinders, saws and abrasive blasters
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High-pressure cleaning machines
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Fans and air-moving devices
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Mowers, blowers and trimmers
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Chain saws and woodchippers
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Pneumatic tools or pneumatic pumps
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Vacuums (indoor or wet/dry)
Some noise hazards can be easy to miss. If you’re used to certain noises, you might not recognize them as a health hazard. To give you an idea of noise exposure and its effect on hearing, look at this list of noise hazards and a few others for comparison.
Personal protective equipment
While equipment and tools differ from workspace to workspace, all PPE aims to protect employees from workplace injuries based on their unique environment. See terminology basics (below) for more information on PPE and noise testing.
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Provide your workers with hearing protection such as earplugs, semi-insert earplugs, earmuffs or advanced hearing protection devices.
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Understand your hearing PPE noise reduction rating and make sure it offers the right amount of protection for the noise exposure.
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Purchase the right PPE for your exposure level.
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Ensure your hearing PPE is certified by the American National Standards Institute (ANSI). Check your PPE for the ANSI logo.
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Allow employees to choose their PPE if possible. This encourages them to wear it. (Earplugs might be more comfortable than earmuffs in hot weather, for example.)
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Train your employees on PPE care and use (like how to insert earplugs properly).
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Properly clean, maintain and store PPE.
PPE and communication barriers
When deciding how to approach noise in the workplace, consider how PPE can diminish speech-based communication on the job. If you can engineer out the noise source, that’s the most effective way to handle noise exposure. But if you cannot dampen the noise at the source, you might have to use a combination of PPE, such as earplugs layered with earmuffs.
Consider hearing protection that aids communication
PPE works for noise exposure, but it also creates a situation where workers can’t communicate verbally. You don’t want them to remove their hearing protection to talk to each other, since this isn’t efficient and only further exposes them to the noise hazard.
Consider using visual cues such as hand signals, or purchase hearing protection that incorporates radio communication systems into the PPE (aka, advanced hearing protection devices).
Engineering out the noise
PPE is the last line of defense for protecting workers from hazards. When you identify a workplace noise hazard, try to engineer out the noise source to cut back or eliminate it. Here are a few ideas:
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Eliminate the noise by removing the noise source.
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Substitute noisier tools or equipment for quieter ones. Check out the NIOSH Buy Quiet website for occupational noise reduction tips and employer resources.
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Isolate or control the noise source. For example, relocate noisy machinery to a room with a door that closes or surround it with sound-absorbing materials.
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Install sound barriers throughout the workplace. These absorb noise or block noise contamination before it enters the general workspace.
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Limit exposure to the noise. For example, change the rotation of work shifts to reduce the number of workers in the area or the time workers spend in the noisy area.
When you can’t feasibly engineer out the noise, use PPE. Give workers earplugs, earmuffs or a combination to layer the protection.
If you have to yell, the noise level is probably over 85 decibels and you need hearing protection.
Distance and time matter
Just because you’re not in proximity to a noise source doesn’t mean you’re in the clear. Think about the workspace, tools and machinery, and how the location of your workers changes during the day. Their job may require them to move between noisy environments and into quieter ones several times each day. Others may work in a continuously noisy environment, but only once a week. That’s the basic idea behind using time-weighted averages (based on an eight-hour workday and 40-hour workweek) and decibels as a measure of occupational noise hazard.
Noise exposure levels can change
A landscaper using a hand-push mower in a quiet neighborhood is exposed to noise levels around 90 decibels. (Some electric mowers emit less noise.) The same landscaper will have a different noise exposure if they’re working as part of a crew using string trimmers and a wood chipper nearby. The crew will have an added level of exposure if they’re working on the grounds of a busy city airport versus a quiet golf course.
Noise-induced hearing loss is cumulative
Noise exposure levels are relative to:
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The tools and equipment a worker uses
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The level of noise emitted by those tools
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The amount of time the worker is exposed to the noise
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The type of exposure
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The added noise contamination from the overall work environment
Dosimeters can be helpful if you’re trying to measure an individual worker’s exposure to noise. Sound level meters are helpful if you want to measure the noise levels in the environment.
Continuous exposure to noise can be as damaging as sudden loud noises, even at lower levels. It’s important to make hearing protection available in all noise hazard areas. If you don’t offer hearing protection for noise hazards, workers may experience noise-induced hearing loss.
Computing noise exposure levels can get complicated, but if you take the time to understand your workers’ job roles and the appropriate PPE, you can create an effective hearing conservation program.
Considerations when choosing PPE
PPE for hearing conservation protects your workers from damaging noise hazards. There are a few things to think about when choosing hearing protection, such as the job role and the environment. Consider the:
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Noise intensity (the loudness of the noise and the pressure put on the ear)
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Frequency of the noise exposure (intermittent or continuous)
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Location of the noise exposure (where the noise is located and whether it changes throughout the workday)
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Comfort of the PPE (more likely to be worn)
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Need to communicate while on the job (Higher levels of noise protection PPE reduce workers’ ability to communicate with one another and may require advanced hearing protection devices.)
Basic terminology
You’ll encounter some terminology in your hearing conservation program research. Here are a few terms to know.
Advanced hearing protection devices — These devices are used when noise levels are unpredictable or when moving between locations. They’re also helpful when workers need to communicate using two-way radios or other means of communication. Advanced hearing protection devices have communication systems built in and allow workers to remain in contact without removing their PPE.
Audiometric test — An audiometric exam is a hearing test that is administered by a certified professional. The test rates each ear for hearing loss across several frequencies.
Audiogram — An audiogram charts the results of the audiometric test. A certified professional evaluates and interprets the results and explains those results to you.
Baseline test — If you’re starting a formal hearing program, you’ll need to test all affected workers at the beginning of the program and annually thereafter. The baseline test is a measure of a worker’s hearing levels working with noise exposure. Baseline tests establish the level of hearing loss, if any, experienced by a worker.
Dosimeter — Dosimeters measure and record noise levels experienced over time. Dosimeters are small meters with a microphone that measures the incoming sound. Workers wear them (usually close to the ear) during their work shift to measure their exposure to noise.Earplugs — Earplugs come in soft, form-fitted materials or as hard plastic plugs. Most are disposable, but a few come in reusable styles. Knowing how to insert earplugs properly is critical.
Earmuffs — These are typically worn over the ear and look like headphones. They can be worn over earplugs for added protection when required.
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Fit testing — You might want to have your hearing protection fitted by a professional. Fit tests customize the hearing protection needed based on the individual worker’s level of noise exposure and hearing requirements (personal attenuation). They provide an added layer of confidence for your workers, and an opportunity for one-on-one training.
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Hearing protector attenuation — The amount of ambient noise that a properly fitted hearing protector reduces. OSHA offers guidance on hearing protector attenuation.
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Noise reduction rating (NRR) — Each hearing protector offers different levels of protection. The NRR is how much noise is blocked by a hearing protector, measured in decibals. The hearing protector manufacturer should display the NRR on the hearing protector package. OSHA offers guidance on using the NRR when calculating hearing protector attenuation.
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Permissible exposure limit (PEL) — The PEL is determined by OSHA. It is the acceptable limit to the noise hazard that a worker can be exposed to.
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Sound level meter (SLM) — Sound level meters measure the noise intensity emitted by a piece of equipment or in an area. They offer a snapshot of noise levels in the work environment, as opposed to an individual exposure level. This is usually measured by a dosimeter.
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Standard threshold shift (STS) — According to OSHA, an STS happens when a worker’s audiogram results show a hearing loss of 10 decibels or more from their baseline audiometric test.
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Temporary threshold shift (TTS) — According to OSHA, a TTS occurs when a worker suffers a short-term, partial temporary hearing loss or ringing in the ears (tinnitus) because of noise exposure.
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Time-weighted average (TWA) — The TWA is based on an eight-hour work shift and a 40-hour work week. OSHA uses it as a baseline to determine permissible exposure limits.
Hearing loss may not hurt during the incident, but it’s a lifetime of loss if you don’t make efforts to prevent it
Ride the wavelength to hearing safety
Now that you’ve got some preliminary information about testing, PPE and establishing a program, give yourself a high-five and keep going. You’re on the right wavelength to hearing conservation safety.
