How is loudness measured? What is a dB?
The unit of measurement used to express the intensity of a sound is the decibel (dB). The intensity of sound and the duration of exposure to the sound contribute to the overall sound energy level to which an individual is exposed. An individual’s risk of losing their hearing depends on how loud, for how long and how often they are exposed to loud sounds. Some common sounds and their intensities (dB) are indicated below.
Heavy city traffic (inside the car)
Hairdryer, subway train, car horn at 5 m
MP3 player at maximum volume, chainsaw
Shouting into the ear
Discotheques, bars and club
Loud rock concerts
Spectator trumpet 1 m from trumpet opening, sirens
Jackhammer, jet plane 30 m away