Night aircraft noise index and sleep research results.

A number of countries have introduced regulations for the protection of people living around airports against the high level of aircraft noise. Certain noise indices have been determined for 24-hour periods, others for extended daytime periods, while a few are weighted for the noise occurring during the night. The noise environment problem limits the development of airports and any reduction of the noise at source is balanced by the increase in air traffic so that the overall noise level around airports remains high. The only possibility for the expansion of traffic is during the night and the airport authorities are interested in this solution for airports that remain open at night and in the case of proposals for some new airports in Western Europe. Research yields some useful results with regard to our understanding of the effects of noise and the duration and quality of sleep of people living around airports. In this paper we consider how these results can be used in proposing some noise criteria corresponding to the preservation of a certain quality of sleep.