On Calculating Average Levels and Level Fluctuating of Street Noise

Fluctuations of traffic noise levels may be characterized by the relative variance of the sound intensity from wich other fluctuation quantities can be derived. It can be calculated for any traffic pattern if the covariance of the spatial sound power density is known.

In this paper formulae are given for the average value and the variance of intensity for open streets as well as for urban roads with buildings along both sides. From these values practically important fluctuation parameters of the noise level can be calculated at least approximately. Then this method is applied to several typical traffic models. Lastly, the possibilities to determine the covariance of the power density are discussed.