- Noise by definition is “sound without value” or “any noise that is unwanted by the
- Noise level is measured in terms of decibels (dB). An increase of about 10 dB is approximately double the increase in loudness.
- W.H.O. (World Health Organization) has prescribed optimum noise level as 45 dB by
day and 35 dB by night. Anything above 80 dB is hazardous.
Effects of noise pollution
Noise pollution leads to irritation, increased blood pressure, loss of temper, mental depression, and annoyance, decrease in work efficiency, loss of hearing which may be first temporary but can become permanent in the noise stress continues.
Prevention and control of noise pollution
- Road traffic noise can be reduced by better designing and proper maintenance of
- Noise abatement measures include creating noise mounds, noise attenuation walls and well-maintained roads and smooth surfacing of roads.
- Retrofitting of locomotives, continuously welded rail track, use of electric locomotives
or deployment of quieter rolling stock will reduce noises emanating from trains.
- Air traffic noise can be reduced by appropriate insulation and introduction of noise
regulations for takeoff and landing of aircraft at the airport.
- Industrial noises can be reduced by soundproofing equipment like generators and areas producing a lot of noise.
- Power tools, very loud music, and land movers, public functions using loudspeakers, etc. should not be permitted at night. Use of horns, alarms, refrigeration units, etc. is to be restricted. Use of firecrackers which are noisy and cause air pollution should be
- A green belt of trees is an efficient noise absorber.
Ambient Noise Level Monitoring
- Noise Pollution (Control and Regulation) Rules, 2000 define ambient noise levels for
various areas as follows:
- The Government of India on Mar 2011 launched a Real-Time Ambient Noise Monitoring Network.
- Under this network, in phase-I, five Remote Noise Monitoring Terminals each have
been installed in different noise zones in seven metros (Delhi, Hyderabad, Kolkata,
Mumbai, Bangalore, Chennai, and Lucknow).
- In Phase II another 35 monitoring stations will be installed in the same seven cities.
Phase III will cover installing 90 stations in 18 other cities.
- Phase-III cities are Kanpur, Pune, Surat, Ahmedabad, Nagpur, Jaipur, Indore, Bhopal,
Ludhiana, Guwahati, Dehradun, Thiruvananthpuram, Bhubaneswar, Patna,
Gandhinagar, Ranchi, Amritsar and Raipur.
- Silence Zone is an area comprising not less than 100 meters around hospitals,
educational institutions, courts, religious places or any other area declared as such by a competent authority.