Value Of Noise Intensity Research Articles

A New Trial to Estimate the Noise Propagation Characteristics of a Traffic Noise System and its Application

Generally speaking, a level-fluctuation of road-traffic noise is brought on by various causes. It is obvious that the ultimate causes are due to a variety of noise sources, i.e., uncertain behavior of individual cars, and to some effect of the noise-propagation characteristics affected by reflections and/or absorptions owing to surrounding buildings and their topographical locations. By dividing the road into a suitable number of blocks, and paying close attention to the mean value of noise intensity in each block, the mean value can be proportional to the number of cars in the block. In this paper, on the basis of the additive property of sound energy, the unified method has been proposed to estimate the inherent characteristics of noise-propagation in each block in the form of a synthetical evaluation with the number of cars for each car-type, also considering the entire back-ground noise. We have confirmed the validity of our theoretical results, not only by means of digital simulation, but also by road-traffic noise-data experimentally observed near Hiroshima City. The experimental results clearly show a good agreement with the values recently reported by other official groups 1) .