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Sound is measured in units called decibels, abbreviated dB.

Loudness is measured on a logarithmic scale, similar to the way the strength of an earthquake is measured logarithmically using the Richter scale. This means that an increase of 10 decibels (dB) represents a 10-fold increase in sound intensity and a doubling of the perceived loudness.

Sounds at or below 70 A-weighted decibels (dBA) are generally safe. Long or repeated exposure to sounds at or above 85 dBA can cause hearing loss. (NIDCH)

  • Normal conversation: 60-70 dBA
  • Lawnmowers: 80 to 100 dBA
  • Sports events: 94 to 110 dBA
  • Sirens from emergency vehicles: 110 to 129 dBA
  • Fireworks: 140 to 160 dBA

A decibel, or dB, is an appraised signal strength in terms of relative loudness heard by the ear. The decibel is 1/10 of a bel, a unit of sound named after Alexander Graham Bell. A change of 1 dB is just detectable as a change in loudness under ideal conditions.

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