What's too loud?

The noise level is dangerously high when you have to raise your voice to talk with someone a few feet away. Or when you can't understand someone speaking to you from less than 2 feet away. Another sign is ringing in the ears or slight deafness for several hours after exposure.

Under rules from the U.S. Occupational Safety and Health Administration (OSHA), employers must offer hearing protection when sound levels average more than 85 decibels in an 8-hour day. OSHA says employers must make sure workers use that protection when sound levels average more than 85decibels in a day. You'll hear about this much noise from a lawnmower, bulldozer, forklift, shop tools, or truck traffic.

The 2 main hearing-protection choices, earplugs and earmuffs, can cut noise by 15 to 30 decibels when correctly fitted. Earplugs protect better against low-frequency noise, such as a loud tractor. Earmuffs do well with high-frequency noise, such as pneumatic tools.

What to do

To provide protection:

• Earplugs must block the ear canal with an airtight seal. So you must choose the right shape and size for your ears. If they won't stay in place, plugs can be fitted to a headband.

• Earmuffs must fit firmly over your entire outer ear to form an airtight seal. They're held in place by an adjustable headband. If you wear them over eyeglasses or long hair, you won't have the correct seal.

• Earplugs and earmuffs can be worn together when noise is greater than 105 decibels. This is louder than a chain saw or pneumatic drill. The combination adds 10 to 15 decibels of protection.

• Noise-canceling earphones are available that actually block background noise. These can be worn when flying, riding in the car (not driving) or other noisy transportation, or in environments with loud background noise.