Any man-made sound that penetrates the environment is noise pollution. Noise pollution can be caused by many sources including highways, vehicles, factories, concerts, air-conditioners, engines, machine, Aircraft, helicopters, alarms, public address systems, industrial development and construction work. In general noise pollution refers to any noise irritating to one's ear which comes from an external source.

Noise pollution can be harmful to animals. High enough levels of noise pollution may interfere with the natural cycles of animals, which may change their migration paths to avoid the sound. Perhaps the most extreme damage caused by noise pollution is the death of marine mammals by the rupturing of various tissues and organs, brought on by the extremely loud (up to 200 decibels) sound of military SONAR.

Persistent infrasonic sound, that is, low frequency sounds can cause physical disturbances to people. For example, diesel generators for refrigerated trucks are a common source for this type of noise pollution.