Harmful Noise Levels

Topic Overview

The effects of noise on hearing vary among people. Some people's ears are more sensitive to loud sounds, especially at certain frequencies. (Frequency means how low or high a tone is.) But any sound that is loud enough and lasts long enough can damage hearing and lead to hearing loss.

A sound's loudness is measured in decibels (dB). Normal conversation is about 60 dB, a lawn mower is about 90 dB, and a loud rock concert is about 120 dB. In general, sounds above 85 are harmful, depending on how long and how often you are exposed to them and whether you wear hearing protection, such as earplugs or earmuffs.

Following is a table of the decibel level of a number of sounds.

Noise levels

Noise	Average decibels (dB)
Leaves rustling, soft music, whisper	30
Average home noise	40
Normal conversation, background music	60
Office noise, inside car at 60 mph	70
Vacuum cleaner, average radio	75
Heavy traffic, window air conditioner, noisy restaurant, power lawn mower	80-89 (sounds above 85 dB are harmful)
Subway, shouted conversation	90-95
Boom box, ATV, motorcycle	96-100
School dance	101-105
Chainsaw, leaf blower, snowmobile	106-115
Sports crowd, rock concert, loud symphony	120-129
Stock car races	130
Gun shot, siren at 100 feet	140

As loudness increases, the amount of time you can hear the sound before damage occurs decreases. Hearing protectors reduce the loudness of sound reaching the ears, making it possible to listen to louder sounds for a longer time.

Preventing damage to your hearing

An easy way to become aware of potentially harmful noise is to pay attention to warning signs that a sound might be damaging to your hearing. A sound may be harmful if:

• You have difficulty talking or hearing others talk over the sound.
• The sound makes your ears hurt.
• Your ears are ringing after hearing the sound.
• Other sounds seem muffled after you leave an area where there is loud sound.

Most cases of noise-induced hearing loss are caused by repeated exposure to moderate levels of noise over many years, not by a few cases of very loud noise. Wearing hearing protectors can help prevent damage from both moderate and loud noise.

If your workplace has harmful noise levels, plan ahead and wear hearing protection. People who may be regularly exposed to harmful noise because of their jobs include:

• Those who work with loud machines, vehicles, or power tools, such as construction workers, factory workers, farmers, truck drivers, mechanics, or airport ground crew workers.
• Military personnel.
• Police officers and firefighters.
• Musicians.