The biggest nuisance is the noise produced by traffic, because its intensity and nature depend upon factors, such as the type of aircraft, vehicle, train and the condition of road, as well as, that of vehicle (in case of automobiles).
In sea traffic, the noise pollution is confined to the harbour due to loading and unloading activities being carried.
Industries cause noise pollution but with varying intensity depending upon the type of industry.
Noise pollution is location specific and its intensity declines with increase in distance.
Noise pollution is hazardous in many metropolitan and big cities in India.