[Importance of the number of events and maximum noise level in evaluating annoyance]

Exposure to environmental noise can cause interference with rest, conversation and listening to radio-TV as well as sleep disturbances. These effects are experienced as annoyance by the exposed person. An analysis of several epidemiological studies on annoyance due to road traffic, train and aircraft noise shows a fair dose-response relationship when the dose is expressed using the traditional indices such as Leq and NNI. An improved relationship is obtained if the dose is expressed in terms of the noisiest even and the number of such events separately. Practical measures to control environmental noise are discussed in terms of this principle.