Hearing Protection

Repeated exposure to loud noise fatigues the hair cells in the inner ear. Just like the reeds, some of these hair cells will return to the normal position, but others will have been damaged beyond the point of recovery. The destruction of these hair cells is evidenced by permanent hearing loss.

Noise induced hearing loss typically occurs gradually and without pain. Often by the time a person realizes that there may be a problem, it is too late. But there are early warning signs.

How Loud Is Too Loud?

Loudness is measured in decibels (dB). Experts recommend that you use earplugs when exposed to 85 dB and above. The following list shows common sounds and their approximate dB levels.

20 dB: Ticking watch

30 dB: Quiet whisper

40 dB: Refrigerator hum

50 dB: Rainfall

60 dB: Sewing machine

70 dB: Washing machine

80 dB: Alarm clock (two feet away)

85 dB: Average traffic

95 dB: MRI

100 dB: Blow dryer, subway train

105 dB: Power mower, chain saw

110 dB: Screaming child

120 dB: Rock concert, thunderclap

130 dB: Jackhammer, jet plane (100 feet away)

Exposure to once-only or continuous noise can cause hearing loss. If hearing recovers, this loss is called temporary threshold shift, which typically disappears after 16 to 48 hours.

Hearing loss can be permanent if loud sounds damage the cells in the inner ear called cilia. Once damaged, these cells cannot be repaired.

SOURCE: American Tinnitus Association