We live in a noisy world. Some noises can damage our hearing, leading to hearing loss, tinnitus (ringing in the ears), and difficulty communicating especially in background noise. Permanent noise-induced hearing damage is incurable. If you cannot reduce your noise exposure by turning down the volume, moving away from the sound, or limiting the time you are exposed, hearing protection is your only option. But hearing protection comes in so many styles, materials, color, and sizes – how can you know which is best for you? National Protect Your Hearing Month is the perfect opportunity to discuss tips for picking the right hearing protector.
Figure 1: Selection of different hearing protection devices – Earplugs, Earmuffs, and Earbands
Obviously, the first consideration in choosing a hearing protector is whether it will block enough noise to reduce your exposure to a safe level. The good news is that most industrial noise exposures are less than 95 dBA, which means most workers require no more than about 10 dB of noise reduction to meet the NIOSH Recommended Exposure Limit of 85 dBA. Almost any hearing protector, when fit correctly, can provide 10 dB of sound reduction. If you do not know the noise levels at your worksite, you can measure them with an app such as the NIOSH Sound Level Meter.
Louder environments demand higher levels of noise reduction, but beware of reducing sound too much. Just as too little light can make it just as difficult to see as too much light, too little sound can make you feel isolated and less aware of their surroundings. Overprotection can be counterproductive, as you may feel the need to remove your hearing protector to hear someone speak or listen to your equipment. Aim for just enough noise reduction to bring your exposure down to 75-85 dBA.
The Noise Reduction Rating on hearing protector packaging represents the amount of noise the hearing protector blocked when tested in a laboratory, but workers usually get much less noise reduction on the job. The best way to know how much noise reduction you are getting from a hearing protector is by fit-testing. If fit-testing is not available at your workplace, you can check earplug fit by counting out loud while slowly cupping and uncupping your hands over your ears; if you have a good fit, your voice should sound about the same as you cup and uncup your ears. NIOSH QuickFitWeb can also be used to check if you are getting more or less than 15 dB of sound reduction.
If you are exposed to noise levels 100 dBA or greater (such as chainsaws or jackhammers) or if you are exposed to impulsive sounds (such as nail gun or weapons noise), you should wear double hearing protection (earmuffs over earplugs).
Workplace characteristics beyond noise levels also need to be considered in choosing the right hearing protector. For example, do you have to wear other head-level personal protective equipment (PPE), such as eye protection, a hard hat, or a respirator? Eye protection (and even some eyeglasses) can interfere with the seal of an earmuff around the ear, allowing sound to leak into the ear. Earmuffs can interfere with the fit of hardhats or helmets; some muffs have a “low-profile” headband or are designed to be mounted directly onto a hardhat or helmet, eliminating this problem. Make sure that your hearing protection is compatible with other safety equipment you use at work.
Consider also whether the noise at your job is continuous or if it stops and starts at various times during the day. Do you stay in the same place for most of the workday, or move from one area to another? Earmuffs are easier to remove and replace than earplugs, so they may be better for intermittent noise exposures. If earmuffs are not an option due to other issues (e.g., compatibility with other PPE), pre-formed earplugs may be easier to remove and replace than foam plugs. Level-dependent or sound restoration hearing protectors can also be useful for intermittent exposures; these types of hearing protection allow sound to pass through when the background noise levels are low and become protective when noise levels increase.
Do your hands frequently get dirty at work? If so, avoid using foam earplugs which must be rolled down with your fingers before insertion, unless hand-washing facilities are readily available and you have time to wash up each time you need to insert the earplugs. Do you work in a tight space? Earmuffs may not be compatible when working in a confined area. Is it very hot or very cold where you work? Earmuffs can be uncomfortable in hot environments; earmuff cushions can become ineffective in very cold environments.
Finally, think about how frequently you need to hear speech while wearing hearing protection. If spoken communication is common, or if high fidelity sound is important for other reasons (e.g., musicians), flat attenuation hearing protectors may be helpful. Special communication headsets can also improve speech communication in very loud environments.
Once you have narrowed your selection down to hearing protectors that are appropriate for your noise exposure and compatible with your worksite and job tasks, the choice is completely up to you! However, hearing protection only works if you wear it consistently and correctly every time you are exposed to hazardous noise, so choose a protector that is comfortable and convenient.
Many people find earplugs more comfortable than earmuffs, especially when worn for long periods of time or in in hot environments. Earplugs are lightweight, easy to store, and convenient to keep on hand for unexpected exposures. However, earplugs may be harder to learn to fit properly. Some earplugs come in different sizes, so you may need help determining which size is correct for you. If your ear canals are very narrow or very curvy, it may be difficult to find an earplug that will fit. Earplugs are usually inexpensive, but they need to be replaced frequently; some earplugs are designed to be used once only and then discarded.
Earmuffs, on the other hand, are generally one-size devices. Many people find them easier to fit properly and consistently. Earmuffs are easier to remove and replace quickly, so they can be preferable for intermittent use. They are bulkier than earplugs and may be uncomfortable in warm places or tight spaces. They are more expensive, but more durable and last longer than earplugs.
Hearing health relies on knowing how to protect your hearing and how to select the right form of hearing protection. This National Protect Your Hearing Month, take a few minutes to make sure you are using the best hearing protection for your work tasks. Then, wear it every time you are exposed to noise levels above 85 dBA. Your ears will thank you!
CAPT William J. Murphy, Ph.D., is a research physicist with the NIOSH Division of Applied Research and Technology.
Christa L. Themann, MA, CCC-A, is a research audiologist with the NIOSH Division of Applied Research and Technology.
CAPT Chucri (Chuck) A. Kardous, MS, PE, is a research engineer with the NIOSH Division of Applied Research and Technology.
CAPT David C. Byrne, Ph.D., CCC-A, is a research audiologist with the NIOSH Division of Applied Research and Technology.
Additional resources:
NIOSH Personal Protective Equipment (PPE)
Best practice bulletin: Hearing protection-emerging trends: Individual Fit Testing
Hearing protection – OSH WIKI
Of all the hazards faced by workers, noise might be the most insidious. Sure, if you’re with 77,000 Kansas City Chiefs fans in Arrowhead Stadium, with crowd noise cranked up to 142.2 decibels, you’re screaming but you can’t be heard. If you’re standing next to a Top Fuel car that breathes fire at more than 150 decibels, you worry about your eardrum shattering.
But if you’re at a nightclub where noise can reach 100dB, are you thinking about dB levels? Just another night out. If you’re pushing a lawnmower with an average noise of 94dB, are you bothered? You’ve mowed the lawn hundreds of times.
Kansas City Chiefs fans set the record for loudest stadium in the world at 142.2 decibelsThat’s the danger of noise. We get acclimated to it, especially at work. And noise does its damage over time, day after day, year after year, killing inner ear hair cells usually without us realizing we’re slowly losing our hearing. Hearing loss is often discovered and recorded in the annual audiogram required by OSHA for each employee exposed at or above an eight-hour time-weighted average of 85dB. The loss is not always painful. Sure, if you’re standing next to a jackhammer or a gun shot blast without wearing hearing protection, that sonic burst can stun you, leaving your ears temporarily ringing.
But 22 million workers in the U.S. are regularly exposed to potentially damaging noise, according to the Centers for Disease Control. OSHA mandates that any workplace averaging 85dB for an eight-hour average exposure must put in place an effective hearing conservation program. (On construction sites it’s a 90dB threshold.) If you need to raise your voice to speak to someone three feet away, noise levels might be above 85dB.
Hearing conservation programs prevent initial occupational hearing loss, protect remaining hearing and equip workers with the knowledge and hearing protection devicesIndustries most cited by OSHA for hearing protection violations:
Protecting and preserving your hearing can make a huge difference in your quality of life. Permanent hearing loss cannot be corrected through surgery or medicine. Hearing aids can help, but they won’t restore your hearing to normal. Your conversations, taken for granted for so many years, may never be the same. Music, movies, TV shows, podcasts, you’ll have to crank ‘em up and hope you don’t annoy whoever is with you.
OSHA requires employers to follow a hierarchy of controls to keep the noise down in workplaces. The first strategy, installing engineering controls such as modifying or replacing equipment, often is not economically or technically feasible. The second option, limiting the time a person spends at a noise source, is often impracticable. Personal protective equipment in the form of hearing protection devices is the most common line of defense.
Concerning hearing protection and the hierarchy of controls, hearing PPE is the most common line of defenseThere is an assortment of industrial hearing protection devices (HPDs) to choose from:
Other noise canceling earmuffs passively block noise by relying on the insulating materials of the ear cups to dampen sound. They're typically worn in areas where workers don't need to speak with one another and the goal is to block all or most surrounding noise. As the NRR of these earmuffs increases, they tend to get bulkier due to the larger ear cups and increased insulation materials.
Keep in mind no single industrial hearing protector fits all people. Devices address a variety of workplaces environments and conditions, including different decibels levels, specific industries, as well as different communication requirements.
The first step in finding the right hearing protection is to determine what the noise level is in your workplace. OSHA requires measuring noise exposure with a sound level meter or noise dosimeter or both. Measurements should be taken at different times to help determine the different noise levels experienced throughout a workday. Employee movement and sound instrument calibration and maintenance should also be considered in a comprehensive measurement program.
OSHA and ANSI’s sound level estimates chart uses a thermometer-type image to rank on the left side job site sound levels as low as a framing saw (82dB), a backhoe (85dB), and up to a bulldozer (100dB), jackhammer (102dB), grader and scraper (107dB) and a chain saw (110dB). On the right side of the thermometer are everyday sound levels, ranging from a whispered voice (30dB), normal conversation (60dB) to a jet engine at takeoff (140dB) and a gunshot (140dB).
Once the noise level of a work area is determined, you can look at the noise reduction ratings (NRR) of hearing protectors to decide how much attenuation is needed to bring the worker’s exposure below the 85dB threshold. The NRR is a common method for expressing values of noise reduction or attenuation provided by different types of hearing protectors; values range from 0 to approximately 30. The higher the NRR number associated with a hearing protector, the greater the potential for noise reduction.
Skullerz 8880 Hard Hat Mounted Earmuffs are tested and certified to 26dB Noise Reduction Rating (NRR)Noise reduction ratings are important because they indicate the functionality of a device, and the ability of that device to protect hearing in noisy environments.
To approximate an NRR, break out a calculator. Industrial hearing protectors do not reduce the decibel levels in the workplace by the precise decibel reduction number on the NRR label because the hearing protector was tested in a lab, not in the field. Say a person working in a loud occupational environment is exposed to noise at 94dB(A). If the individual is wearing hearing protection equipment with an NRR of about 26dB(A), you would think the noise exposure amount would be lowered to 68dB(A). Wrong. Instead, it would be lowered to 84.5dB(A), below the OSHA threshold of 85dB. How is this calculated? OSHA has methods for estimating the adequacy of hearing protection attenuation. One method’s calculation includes:
What if you are wearing two sets of ear protectors? How is the NRR calculated? This method’s calculation includes:
Training on the proper use of hearing protectors should include individual fit testing to measure how well the devices fit each person.
So what’s best for you? Disposables or reusables? Earplugs or earmuffs? The first thing to do is find adequate protection. Second, make sure the hearing protector is compatible with other PPE or communication devices. And then there is the age-old challenge of compliance – making sure the hearing protection is comfortable and convenient enough to be accepted and worn, not found dangling around the neck, stuffed in a pocket or flipped up on hard hats. Despite decades of knowledge about the dangers of high noise and hearing loss, NIOSH declares occupational hearing loss the most common U.S. work-related illness in manufacturing.
Skullerz 8880 Earmuffs are designed for easy Ergodyne Hard Hat and Safety Helmet integrationProvide your employees with the opportunity to select their hearing protection from a variety of suitable devices. This is a mandate in OSHA noise standard. And it’s one OSHA mandate easily met.
The marketplace for industrial hearing protection features all the types of protection needed for any situation. One example, Skullerz 8880 NRR 26dB Hard Hat Mounted Earmuffs, designed for all-day comfort and for hard hat and safety helmet integration.
Triple up on protection by adding a face shield, earmuffs and a headlamp to Skullerz Hard Hats and Safety Helmets