Noise, by definition, is unwanted sound. What is pleasant to some ears may be extremely unpleasant to others, depending on a number of factors.

The natural environment contains many sources of noise, i.e., wind, volcanoes, oceans and animal sounds are all familiar intrusions accepted at various levels. Man-made noise – such as those from machines, automobiles, trains, planes, explosives, and public address system, music system, bands, firecrackers, etc. are more contentious.

The direct physiological effects of noise include a loss of hearing, either temporary or permanent. The non-auditory effects include cardiac ailments, stress and fatigue, and sleep disturbances. Among the psychological effects documented by experts are a lack of concentration, loss of memory and an adverse impact of the education of children. Noise is also suspected of aggravating nausea, headache, insomnia and a loss of appetite.

Noise travels through the air. Noise is measured in decibels (dB). Experts believe that continuous noise levels in excess of 90 decibels can cause loss of hearing and irreversible changes in nervous systems. The world Health Organization (WHO) has fixed 45 decibels as the safe noise level for a city.

The typical noise levels are: Forest – 20 dB, Living room – 40 dB, Business office – 65 dB, Noisy workplace – 85 dB, Pneumatic hammer/chipper – 100 dB, Rock group- 110 dB, Sound emitting fire crackers- 125 dB, and air craft take off 135 dB (25 m. Distance).

The Environment (Protection) Act of 1986 (EPA) recognizes noise as an environmental pollutant and empowers the Central Government to frame rules prescribing the maximum permissible limits for noise in different areas. On 14th February, 2000, the Central Government notified the Noise Pollution (Regulation and Control) Rules, 2000.

Two types of noise standards are prescribed: ambient air quality standards in respect of noise and emission limits for designated types of machinery, appliances and fire crackers. The noise emission standards related to equipment(s) are prescribed in Schedule VI of the Environment (Protection) Rules of 1986 which are related to motor vehicles, air conditioner, refrigerator, diesel generators and certain types of construction equipments.