Hearing Protectors | NIDCD

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What are hearing protectors?

The best ways to protect your hearing are to avoid exposure to loud sounds, move away from the noise, or turn down the volume. When these options aren&#;t possible, hearing protectors&#;earplugs or protective earmuffs&#;can help. Hearing protectors are wearable devices that can lower the intensity of sound that enters your ears.

Why is it important to protect your hearing?

Loud sounds can damage sensitive structures in your inner ear, causing noise-induced hearing loss (NIHL) and tinnitus (ringing, roaring, or buzzing in the ears). The louder the sound, the faster it can damage your hearing.

NIHL is a significant health problem for U.S. youth and adults. According to the Centers for Disease Control and Prevention (CDC), self-reported hearing tests show that about one in seven U.S. teens and nearly one in four U.S. adults (ages 20 to 69) have features suggestive of NIHL in one or both ears.

Hearing damage can happen instantly. The sound of a gunshot at close range, for example, can cause immediate and permanent damage. Other types of very loud sounds can cause hearing loss in less than 15 minutes. Exposure to repetitive loud noise&#;from machinery at a worksite, for example&#;may result in hearing loss over time.

How loud is too loud?

Sound is measured in units called decibels. Sounds at or below 70 A-weighted decibels (dBA) are generally safe. A single very loud noise or long or repeated exposure to sounds at or above 85 dBA can cause hearing loss. Here are average decibel ratings for a few familiar sounds:

• Normal conversation: 60 to 70 dBA
• Lawnmowers: 80 to 100 dBA
• Motorcycles and dirt bikes: 80 to 110 dBA
• Music through headphones at maximum volume, sporting events, and concerts: 94 to 110 dBA
• Sirens from emergency vehicles: 110 to 129 dBA
• Fireworks displays: 140 to 160 dBA

The Sound Level Meter app developed for iOS devices by the CDC&#;s National Institute for Occupational Safety and Health (NIOSH) is one example of a free decibel meter app that can help you evaluate sound risks in your environment. 

When should you wear hearing protectors?

If you anticipate being in a loud setting or participating in a noisy activity, wear earplugs or protective earmuffs to safeguard your hearing. Hearing protectors are recommended for these settings and activities:

• Auto races, sporting events, fireworks displays, and concerts.
• Motorcycle, dirt bike, and snowmobile riding, and when operating an all-terrain vehicle or tractor.
• Band or orchestra rehearsals and performances.
• Industrial, warehouse, farm, landscape, and other loud (or potentially loud) workplace settings.
• Shooting sports.

Make it a habit to wear hearing protectors when you expect to be in a loud setting, and keep earplugs or protective earmuffs handy for unexpected loud noises. If loud noise happens suddenly or unexpectedly, cover your ears with your hands and move away from the noise, if possible.

What types of hearing protectors are available?

Earplugs and protective earmuffs are available from retail stores or online. Examples include formable foam earplugs, pre-molded earplugs, canal caps, and safety earmuffs. &#;Musician earplugs&#; are custom-made earplug molds intended to protect hearing while also allowing as much natural sound as possible to safely enter the ear. Choose a type of hearing protector that is comfortable and easy for you to use, so that you will use it consistently and correctly.

Hearing protectors don&#;t block all sound. Most hearing protectors have a noise reduction rating (NRR). In general, the higher the NRR, the more sound is blocked (if you are wearing the device correctly). Choose hearing protectors that allow you to communicate well in a noisy environment, so that you don&#;t have to remove them during conversation. Even briefly removing your hearing protectors in a very loud environment puts your hearing at risk.

Consult a hearing health professional if you need help selecting hearing protection, or for information about custom-made earplugs.

Earplugs

Earplugs are inexpensive devices placed directly into your ear canal. Earplugs come in various sizes, but can be hard to find in sizes that fit children. Earplugs may have cords attached to help you keep track of them. Specialty earplugs, including earplugs that are custom-molded to your ears, are also available.

• Formable foam earplugs are made of soft foam. Once inserted, these earplugs expand to fill your ear canal snugly. Formable foam earplugs are meant for one-time use, but they can be reused if they are clean and still fully expand to their &#;like new&#; shape.

  
  Formable foam earplugs

• Pre-molded earplugs are made from plastic, rubber, or silicone. One type of pre-molded earplug is high-fidelity (hi-fi) earplugs, also called uniform-attenuation earplugs. They have the same effect as turning down the volume on a stereo: the sound intensity is evenly decreased across different pitches. You might find high-fidelity earplugs especially helpful at movies or concerts and at other times when you want to appreciate the audio quality while protecting your hearing.

  
  Pre-molded, high-fidelity earplugs

• Canal caps have a stiff band that provides a gentle force to seal the earplugs, whether formable or pre-molded, into your ear canal. When not in use, the band can be worn around your neck. 

  
  Canal caps

How to use formable foam earplugs:

1. Gently roll the earplug between your fingers into a thin tube shape, taking care not to crease the foam, which can create tunnels for sound to enter.
2. Pull the top of your ear up and back with your opposite hand to straighten your ear canal and make it easier to insert the earplug.
3. Continue to roll the earplug and gently slide it into your ear canal. It should fit evenly across the opening of your ear.
4. Gently hold the earplug in place with your finger for 20&#;30 seconds to give it time to expand.
5. Check the fit to make sure the earplug is comfortable and properly inserted in your ear canal. The earplug should barely be visible when positioned correctly.
6. Repeat steps to insert the earplug into your other ear.
7. Do not cut or tear foam earplugs to make them fit. Cutting the foam reduces its effectiveness. If foam earplugs can&#;t be inserted properly, consider another kind of hearing protector.
8. To remove foam earplugs, slowly twist to break the seal with your ear canal, and then gently take them out of your ear.

How to use pre-molded earplugs:

1. Gently pull the top of your ear up and back with your opposite hand to straighten your ear canal.
2. Use the other hand to firmly grip the stem of the earplug and gently slide the earplug into the ear canal, using a rocking motion until you have sealed the ear canal.
3. To remove pre-molded earplugs, slowly rock them back and forth to break the seal with your ear canal, and then gently pull them out of your ear.

How to use canal caps:

1. Place the band around your head so that the earplugs are accessible to your ears.
2. Insert one earplug at a time.
3. Gently pull the top of your ear up and back with your opposite hand to straighten your ear canal.
4. Insert the tip of the cap into your ear and gently apply pressure until the cap is firmly in place.
5. If the tips are made of foam, use gentle pressure to roll the foam tip between your fingers into a thin tube shape before inserting.
6. Using the same process, insert the second canal cap into your other ear.

Proper fit is important for successful hearing protection. After inserting earplugs, your voice should sound different to you&#;possibly louder and/or muffled. The earplugs should feel comfortable and secure in your ears. Ask a friend or use a mirror to check positioning. You may need to practice for a comfortable, secure fit. Wearing earplugs shouldn&#;t be painful. Never force earplugs into your ears. If you can&#;t secure a comfortable fit, consider using protective earmuffs instead.

Protective earmuffs

Protective earmuffs are easy-to-use, padded plastic and foam cups joined by an adjustable headband. (They aren&#;t the soft earmuffs worn for warmth.) They reduce noise by completely covering both ears. Sizes for adults and children are available. Earmuffs are easier than earplugs to use correctly, especially for young children.

Earmuffs might not work as well for people who wear glasses because the arms of the glasses can create gaps between the earmuff cushion and the skull. If you wear glasses, check to make sure the earmuffs seal properly. Hairstyles, hats, and facial hair can create gaps that make protective earmuffs less effective.

Protective earmuffs

How to use protective earmuffs:

1. Grasp one cup of the earmuffs in each hand and gently pull apart.
2. Place the band over the top of your (or your child&#;s) head and slowly release the cups, making sure they completely cover the ears and fit snugly. Some earmuffs have adjustable headbands to help secure the fit. 

What research is being done on hearing protection?

The National Institute on Deafness and Other Communication Disorders (NIDCD), part of the National Institutes of Health (NIH), supports research on the causes, diagnosis, treatment, and prevention of NIHL. The NIDCD also supports research to increase accessible, affordable hearing health care.

Where can I find more information on hearing loss and protection?

The NIDCD maintains a directory of organizations that provide information on the normal and disordered processes of hearing, balance, taste, smell, voice, speech, and language.

For more information, contact us at:

NIDCD Information Clearinghouse
1 Communication Avenue
Bethesda, MD -
Toll-free voice: (800) 241-
Toll-free TTY: (800) 241-
: 

NIH Pub. No. 20-DC-
November

How can I protect my hearing at work?

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The surest method of preventing noise-induced hearing loss (NIHL) is to eliminate the source or to reduce noise at the source by engineering methods. However, in certain situations, these measures are not possible. In such workplaces, workers may need to wear hearing protectors to reduce the amount of noise reaching the ears.

What are some things I should know about selecting hearing protection devices?

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People should wear a hearing protector if the noise or sound level they are exposed to is close to or greater than the occupational exposure limits (OEL) for noise. For most jurisdictions, this occupational exposure limit is 85 decibels (A-weighted) or dBA. Hearing protectors reduce the noise exposure level and the risk of hearing loss when worn correctly.

If hearing protection is required, then a complete hearing conservation program should be implemented. A hearing conservation program includes noise assessment, methods for controlling noise, hearing protector selection, employee training and education, audiometric testing, maintenance, inspection, record keeping, and program evaluation.

The effectiveness of hearing protection is reduced greatly if the hearing protectors do not fit properly, are not inserted or worn correctly, if they are worn only periodically, or if they are removed even for a short period of time. To maintain their effectiveness, the hearing protection should not be modified. Music earphones or headsets are not substitutes for hearing protectors and should not be worn where hearing protectors are required to protect against exposure to noise.

Select hearing protection that is:

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• Correct for the job. Refer to the Canadian Standards Association (CSA) Standard Z94.2-14 (R) &#;Hearing Protection Devices - Performance, Selection, Care and Use&#; or contact the agency responsible for occupational health and safety legislation in your jurisdiction for more information.
• Adequate for the protection or noise attenuation required. Check the manufacturer's literature.
• Compatible with other required personal protective equipment, or communication devices.
• Comfortable enough to be worn.
• Appropriate for the temperature and humidity in the workplace.
• Able to provide adequate communication and audibility needs (e.g., the ability to hear alarms or warning sounds).

What types of hearing protectors are available?

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Earplugs are inserted in the ear canal. They may be premolded (preformed), moldable, rolldown foam, push-to-fit, or custom molded. Disposable, reusable and custom earplugs are available.

Semi-insert earplugs consist of two earplugs held over the ends of the ear canal by a rigid headband.

Earmuffs consist of sound-attenuating material and soft ear cushions that fit around the ear and hard outer cups. They are held together by a headband.

How do I pick my hearing protectors?

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The choice of hearing protectors is a very personal one and depends on a number of factors including level of noise, comfort, and the suitability of the hearing protector for both the worker and the environment. Most importantly, the hearing protector should provide the desired noise reduction. It is best, where hearing protectors must be used, to provide a choice of a number of different types and sizes to choose from.

If the noise exposure is intermittent, earmuffs are more desirable since it may be inconvenient to remove and reinsert earplugs. 
 

How can I find out how much a hearing protector can reduce a worker's exposure to noise?

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Manufacturers provide information about the noise-reducing capability of a hearing protector, referred to as an NRR (noise reduction rating) value. The NRR is based on laboratory conditions, therefore, calculations to de-rate the noise reduction rating should be done to reflect workplace conditions (see further below).

CSA Standard Z94.2-14 (R) &#;Hearing protection devices &#; Performance, selection, care, and use&#; defines noise reduction rating as &#;a single number rating that indicates the overall hearing protector attenuation, computed as the difference between the overall C-weighted level of a noise spectrum having equal energy per octave and the A-weighted noise levels under a hearing protector, using mean attenuation data less two standard deviations, derived from the experimenter-fit-procedure of the edition of ANSI Z3.19 (withdrawn) as defined in EPA ()&#;. 

How do I use Noise Reduction Rating (NRR) values to determine the protection provided by a hearing protector?

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The NRR, or other similar systems such as the single number rating (SNR), is a method to more accurately determine the effective exposure of a person when wearing a hearing protector. These rating systems attempt to estimate the actual sound protection provided by hearing protectors when worn in actual working environments (vs. laboratory testing situations). The &#;real world&#; results are often different than laboratory tests with the main reasons for this difference being poor fit, and lack of proper training, supervision, and enforcement. For these reasons, training on the correct fit, and making sure users have a thorough understanding of hearing loss are important elements of the hearing conservation program.

Detailed calculations of the protection provided by a hearing protector involve using octave band analysis of the workplace noise and the noise attenuation provided by the hearing protector for noise in each octave band. Attenuation is defined by CSA Standard Z94.2-14 (R) &#;Hearing protection devices &#; Performance, selection, care, and use&#; as &#;the reduction in sound pressure level incident upon the ear due to the application of a hearing protector or, specifically, the change in hearing threshold level that results when a hearing protector is worn.&#;

Calculating noise attenuation of hearing protection and de-rating noise reduction values (NRR)

Source: CSA Z94.2-14 (R) &#;Hearing protection devices &#; Performance, selection, care, and use&#; Table 2

Earplugs 
Percent of NRR achieved: 50% 
For use with dBA: Leq &#; [NRR (0.50) &#; 3] = XX dBA 
For use with dBC: Lceq &#; NRR (0.5) = XX dBA

Earmuffs 
Percent of NRR achieved: 70% 
For use with dBA: Leq &#; [NRR (0.7) &#; 3] = XX dBA 
For use with dBC: Lceq &#; NRR (0.7) = XX dBA

Dual Protection (use of earplugs and earmuffs) 
Percent of NRR achieved: 65% 
For use with dBA: Leq&#; [(NRR + 5) (0.65) &#; 3] = XX dBA 
For use with dBC: Lceq &#; (NRR + 5) (0.65) = XX dBA

The NRR used for dual-protection calculations is higher of the individual NRRs of the two devices. 
Note: Certain CSA Group standards are available for online viewing. To access these, you must first create an account with &#;CSA Communities&#;.

Go to: "https://community.csagroup.org/login.jspa?referer=%252Findex.jspa" 
Once you are logged in, click on the text below the &#;OHS Standards / View Access&#; graphic. 
Click on the jurisdiction of your choice to see the CSA Standards as referenced in that legislation. 
Standards may also be purchased from CSA Group: "https://store.csagroup.org/"

As an example:

Measured workplace noise time-weighted average (TWA) exposure = 98 dBA 
Earplug with NRR = 29 dB 
Estimated noise exposure = 98 &#; [29(0.5) - 3] = 86.5 dBA

CSA Standard Z94.2-14 (R) provides further guidance on how to apply NRR calculations.

What is a Single Number Rating (SNR)?

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Both types of hearing protection offer advantages and disadvantages.

Earplugs can be mass-produced or individually molded to fit the ear. They can be reusable or disposable. On the positive side, they are simple to use, less expensive than muffs, and often more comfortable to wear when in hot or damp work areas. Some disadvantages are they provide less noise protection than some muffs, and should not be used in areas exceeding 105 dBA. Earplugs are less visible than  muffs, making it more difficult to confirm if they are worn. They must be properly inserted and inserted hygienically to provide adequate protection.

Earmuffs can vary with respect to the material and depth of the dome and the force of the headband. The deeper and heavier the dome, the greater the low-frequency attenuation provided by the protector. The headband must fit tightly enough to maintain a proper seal, yet not be too tight for comfort. Some advantages are that earmuffs usually provide greater protection than plugs, although this is not always true. They are easier to fit, generally more durable than plugs, and they have replaceable parts. On the negative side, they are more expensive and often less comfortable than plugs, especially in hot work areas. In areas where noise levels are very high, muffs and plugs can be worn together to give better protection.

The following table summarizes the differences between earplugs and earmuffs.

Comparison of Hearing ProtectionEarplugsEarmuffs 

Advantages:

• small and easily carried
• convenient to use with other personal protection equipment (can be worn with earmuffs)
• more comfortable for long-term wear in hot, humid work areas
• convenient for use in confined work areas 
   

Advantages:

• less attenuation variability among users
• designed so that one size fits most head sizes
• easily seen at a distance to assist in the monitoring of their use
• not easily misplaced or lost

• may be worn with minor ear infections

 

 

Disadvantages:

• requires more time to fit
• more difficult to insert and remove
• requires good hygiene practices
• may irritate the ear canal
• easily misplaced
• more difficult to see and monitor usage

Disadvantages:

• less portable and heavier
• more inconvenient for use with other personal protective equipment.
• more uncomfortable in hot, humid work area
• more inconvenient for use in confined work areas
• may interfere with the wearing of safety or prescription glasses: wearing glasses results in breaking the seal between the earmuff and the skin and results in decreased hearing protection.

Why is user preference so important?

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The human aspects of hearing protection are particularly important since the only useful kind of protection is the protection that is actually worn. Some people do not accept particular kinds of protectors; every human being is different, and the anatomy of the ear and ear canal can vary significantly from person to person.

It is a good idea for the employer to provide a number of different types and sizes of hearing protection from which workers can choose, keeping in mind any safety or hygienic reasons for not providing a particular kind of protector. That is, a particular type of protector should not be used if noise levels are too high or if it proves to be inadequate from a hygienic point of view. For example, earplugs which are used in a plant setting where people reuse them throughout the day, often reinserting them with dirty fingers, can introduce dirt and bacteria into the ears, causing ear infections.

The bottom line on hearing protection is worker preference. If the workers do not like the type of protection (for example, if it is uncomfortable, does not fit well, or is impractical), they will not wear it.

What should I know about the fit of my hearing protectors?

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 Follow the manufacturer's instructions. With earplugs, for example, the ear should be pulled outward and upward with the opposite hand to enlarge and straighten the ear canal, and insert the plug with clean hands.

• Ensure the hearing protector tightly seals within the ear canal or against the side of the head. Hair and clothing should not be in the way.

What happens to the protection level when hearing protectors are removed for short periods of time?

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In order to get the full benefit, hearing protectors must be worn all the time during noisy work. If hearing protectors are removed only for a short duration, the protection is substantially reduced. The following table gives a maximum protection provided for non-continuous use of an ideally fitted 100% efficient hearing protector. For example, when hearing protection is rated with an attenuation of 25dB, if one takes off their hearing protector for 5 minutes in an hour the maximum protection will be reduced to no more than 11dB.

Impact of removing hearing protectorTime removed (in 1 hr)Maximum 25 dB protection is reduced to (dB)0 minno reduction1 min175 min min830 min360 min0

Source: Removal of hearing protectors severely reduces protection. Health and Safety Executive, UK (no date)

Hearing protectors must be used ALL THE TIME to get the full benefit.

How should I care for my hearing protection device?

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• Follow the manufacturer's instructions.
• Check hearing protection regularly for wear and tear.
• Replace ear cushions or plugs that are no longer pliable.
•  Replace the device when headbands are so stretched that they do not keep ear cushions snugly against the head.
• Disassemble earmuffs to clean.
• Wash earmuffs with a mild liquid detergent in warm water, and then rinse in clear warm water. Ensure that the sound-attenuating material inside the ear cushions does not get wet.
• Use a soft brush to remove skin oil and dirt that can harden ear cushions.
• Squeeze excess moisture from the plugs or cushions, then place them on a clean surface to air dry. (Check the manufacturer's recommendations first to find out if the earplugs are washable.)
   

 

 

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• Fact sheet last revised: -06-08