What is Noise Pollution?

Noise, basically, is unwanted or nuisance sound. Noise pollution is a displeasing human- or machine-created sound that disrupts human or animal life.

Noise pollution comes in a variety of forms. A continuous noise such as a ventilation system may be quite loud, but its consistency means that it often goes unnoticed. Intermittent noises like trains and cars come and go at random intervals. These noise sources are loud and disruptive. The most intrusive kind of noise pollution is the impulsive noise. A firecracker is an example of an impulsive noise, because its suddenness is what makes it so disturbing.

Noise or sound is measured in decibels, dB. The basic instrument used for the measuring of noise is the sound level meter. This instrument is designed to respond in approximately the same way as the human ear and gives objective assessment of sound pressure level. Usually 80 db is the level at which sound becomes physically painful.

A mechanism known as "A-weighting" has been adopted in order to account for this non-linearity of the human ear. Sound levels expressed using "A-weighting" are typically denoted dB(A). An indication of the level of some common sounds is shown below: