Definitions

Noise pollution (or environmental noise) is displeasing human, animal or machine-created sound that disrupts the activity or balance of human or animal life.
Noise pollution is a type of energy pollution in which distracting, irritating, or damaging sounds are freely audible. The definition of noise pollution is open to debate, and there is no clear border as to which sounds may constitute noise pollution. In the most narrow sense, sounds are considered noise pollution if they adversely affect wildlife, human activity, or are capable of damaging physical structures on a regular, repeating basis. A sound may be considered noise pollution if it disturbs any natural process or causes human harm, even if the sound does not occur on a regular basis.
Noise pollution is the intrusion of unwanted, uncontrollable, and unpredictable sounds, not necessarily loud, into the lives of individuals of reasonable sensitivities. Noises are especially bothersome at night when one is trying to sleep, and a good night's sleep is vital to good health.