Sound is measured in decibels (dB). An increase of about 10 dB is approximately double the increase in loudness.
A person’s hearing can be damaged if exposed to noise levels over 75 dB over a prolonged period of time.
The World Health Organization recommends that the sound level indoors should be less than 30 dB.
Ambient Noise Level Monitoring – Noise Pollution (Control and Regulation) Rules, 2000 define ambient noise levels for various areas as follows-
- Industrial Area—75DB to 70Db (Day time-6am to 10pm and night time 10pm to 6am ..75 is day time and 70 is night time)
- Commercial Area–65 to 55
- Residential Area–55 to 45
- Silence Zone– 50 to 40
- 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 metres around hospitals, educational institutions, courts, religious places or any other t area declared as such by a competent authority.