What Is an NRR Rating on Hearing Protection?

In a split-second the blast from a gun can damage your ears and cause permanent hearing loss. In one afternoon, your ears can be damaged from mowing the lawn.

You can reduce the chances of losing your hearing by using hearing protection devices. Before you run out to the store, do your homework. Start by selecting the earplugs or earmuffs for the noise you will be exposed to. Then choose the appropriate NRR rating.

Definition

• NRR stands for Noise Reduction Rating and is the greatest amount of sound reduction that a hearing protection device can provide.

  A higher NRR decibel (dB) rating means a greater amount of noise reduction. For example, an earplug with a noise reduction rating of 29 dB provides more protection than an NRR 25 earplug.

When To Use Ear Protection

• A noise may be potentially hazardous when you have to raise your voice for someone to hear you at one arm's length away.

  When your ears ring or sounds seem muffled after leaving a noisy place, then you were exposed to dangerously loud noise.

  The rule of thumb is that any sound at 85 dB or louder is hazardous to your ears.

Types of Loud Noise

• Firearms, jet engines and concert noise can be as loud as 140 dB. However, your ears are susceptible to damage from lawnmowers, power tools, subway noises and truck noises that are 90 dB or louder.

  Chainsaws, snowmobiles and heavy machinery range from 100 to 110 dB, while motorcycles and amplified music can be as loud as 120 dB.

Exposure Time

• It takes 8 hours of exposure to an 85 dB noise for ear damage to occur. It doesn't matter what kind of sound it is.

  For every 3 dB louder than 85 dB, it takes only half the exposure time for damage to set in. For example, an 88 dB sound will damage your ears in 4 hours. A 91 dB sound will cause damage in 2 hours. So you will suffer ear damage and hearing loss when mowing your lawn for 2 hours or more.

Types of Ear Protection

• Hearing protection devices (HPDs) are earplugs and earmuffs. Earplugs can be made of foam or a polymer. Foam plugs are shaped like small cylinders that you roll and compress then insert into your ear canal. Polymer plugs are "rubbery" and have flanges or fins.

  Earmuffs have a cup design with noise dampened cushions that surround the ear to seal off noise. Some earmuffs are designed to accommodate hardhats. Some allow radio communication with others who have the same type of earmuffs.

  Custom earplugs are custom-made for your ears by an audiologist. Custom earplugs are comfortable and provide maximum protection.

Special Hearing Protection Devices

• Most hearing protection devices are designed for industrial noise to protect the ears from the types of sounds generated in factories and on construction sites. They are not appropriate for shooting firearms or for musicians.

  Musicians' ear plugs are specially designed to preserve the frequencies and sound quality while providing protection. Shooting earplugs and earmuffs have a special valve design to protect the ears from the sudden explosive noise produced by firearms.