Noise pollution or
noise disturbance is the disturbing or excessive
noise that may harm the activity or balance of human or animal life. The source of most outdoor noise worldwide is mainly caused by
machines and
transportation systems,
motor vehicles,
aircraft, and
trains. Outdoor noise is summarized by the word
environmental noise. Poor
urban planning may give rise to noise pollution, since side-by-side industrial and residential buildings can result in noise pollution in the residential areas. Documented problems associated with urban noise go back as far as Ancient Rome.