Volume

Volume is expressed in decibels.
When a noise level increases by 3 dB, it is in fact twice as loud.

sound sources volume
(in dB)		 consequences questions
a noise of an aeroplane 140 destruction
of the inner ear 		What unit is used to measure
volume?
the
  130
a power pick 120 pain threshold
a rock'n'roll concert 110 danger zone

risks of lesions
to the ear

heavy traffic 100
a motorbike or truck 90
a car, the noise of a crowd 80 zone of tiredness
a loud conversation,
up to 50 cm away 		70
a busy street through
an open window
 60
a normal conversation,
about 3 m away 		50 light noise
background noises 40
a rustle of leaves 30
a quite conversation,
up to 10 cm away 		20
whispers 10
hardly audible 0