Noise has many possible sources: trains going past, aircraft taking off, traffic, household appliances, building site machinery, etc.

Each noise can be measured on a scale.

Excessive noise = danger

A loss of hearing is possible from 80 decibels (dB) if the exposure to noise continues over too long a period. At 120 dB and above, damage may be irreversible. Inside a car, noise is considered as low up to around 67 dB. It becomes loud from 73 dB, and intense from 79 dB.

Cars are among the many sources of noise that contribute to the noise environment.