An imbalance in a SOUNDSCAPE caused by intruding or disrupting sound of any kind. Such an intrusion need not necessarily be excessively loud (as recorded on a SOUND LEVEL METER for instance), but rather it needs only to have characteristics which disturb the perceived balance of a soundscape.
In this sense, the nature of sound pollution depends largely on how an observer perceives the original balance and the nature of the SOUND INTRUSION. For example, a transistor radio in a quiet rural or park area is often perceived as disrupting the natural soundscape, even if it is not excessively loud (see SCHIZOPHONIA); it is perceived as simply being out of place, since it overpowers or MASKs quieter sounds, and cannot be easily ignored by the listener. Even less consciously perceived sounds, such as low frequency AMBIENT SOUND, may affect the balance of a soundscape and human behaviour within it over the long term.
See also: LO-FI, MOOZAK, SOUNDSCAPE DESIGN, WORLD SOUNDSCAPE PROJECT. Compare: JET PAUSE, NOISE, NOISE POLLUTION, SACRED NOISE, SILENCE, SOUND EVENT, SOUND PHOBIA, SOUNDWALK, TEMPO, TUNING.