Noise (environmental)

Noise is unwanted sound. This is however subjective: some sounds are considered noise by some but not by others, e.g. certain music, church bells, calls to prayers from a minaret, sounds of playing children, birds, wind, sea, etc.

It is one of the most underestimated causes of health damage. There are several kinds of noise by source, including aviation noise, car noise[?], train noise[?] and industrial noise[?].