Excessive noise is an issue of considerable concern to those living close to airports. Two different ways are used to describe air traffic noise- the equivalent level (which is the average value during a certain period of time) and the maximum level (which occurs at specific times). Air traffic noise is usually very irritating when approaching the maximum level. Aircraft noise is a particularly irritating form of pollution, since the noise from a single aircraft flying over a town or city can reach into all parts of it at disturbing levels. About 0.5% of the population in European countries and Japan are exposed to noise levels from aircraft in excess of 65dB, while in the United States about two percent of the population (i.e. five million people) are effected (OECD, 1991).

In the context of the proposed construction of airport at Lengpui, Mizoram Messrs. Engineers and Management Associates (EMA), New Delhi, who are providing consultancy services for Master Planning and Design for the above airport, have dealt with the issue of Noise Exposure Forecast (NEF) and Landuse Compatibility in an elaborate manner and have taken into account the guidelines provided by the DGCA. Currently, at Lengpui there is no forecast of noise exposure which can lead to negative impacts on the surrounds of the project site. The Lengpui airport is located in an area where population is scarce and only a few hamlets exist along the glide path, funnels and conical surface.

Noise from aircrafts can also have varying impacts on wild animals (Krausman et. al., 1986; Mac Arthur et. al., 1982). The impacts generally range from migration of animals to reduction in foraging efficiency (Stockwell, et. al., 1991).

Since the reports of the State Forest Department and our own observations in the project area do not confirm the presence of wild animals in significant numbers, the impacts of aircraft noise on the wilderness quality of the area are not being perceived to be of a serious nature.