Preventing Noise-Induced Hearing Loss

Loudness is measured in decibels on a logarithmic scale. This means that 10 decibels represents a 10-fold difference in sound intensity. That is, 20 decibels is 10 times as loud as 10 decibels, and 30 decibels is 100 times as loud as 10 decibels. Interestingly, although an increase in volume of 10 decibels represents a 10-fold increase in volume, it only seems twice as loud to the person hearing it.

Glycerin-filled earmuffs, headphones, or plastic or foam rubber earplugs can be used to protect the ears from noise that can cause hearing loss. Such protection is recommended if exposure exceeds the following durations and noise levels: 8 hours at 85 decibels; 2 hours at 100 decibels; 15 minutes at 115 decibels; any exposure that exceeds 115 decibels. In addition, music should be played at moderate or low volume levels, particularly when headphones are used.

Decibels:   Example

  30:    Whisper, quiet library
  60:    Normal conversation, sewing machine, typewriter
  90:    Lawnmower, truck traffic
100:    Chainsaw, snowmobile
115:    Automobile horn
140:    Gun muzzle blast, jet engine