Classification of relative influence of physical parameters for long range acoustic propagation - Experimental and numerical results

Predictions of sound pressure levels at medium and large distances from road, railway and industrial sources has been of considerable interest in environmental acoustics for several years. Following the demand for research proposals from the French Ministry of Ecology and Sustainable Development, a research project called "classification of relative influence of physical parameters for long range acoustic propagation" has started in 2004 April 1st. The aim is to study the influence of micrometeorology and impedance changes on sound propagation from road, rail and industrial noises, by using both experimental and numerical results, in order to give easy usable elements to evaluate the sensitivity of a given configuration. In this purpose an important experimentation has been conducted during three months, with roughly one hundred meteorological and acoustical sensors. The experimentation is presented in this paper, and the process of cleaning the data is detailed. The results will provide a basis for a classification method for the main parameters in typical acoustical situations. One of the outcome is to apply this method in standardization works in which most of the partners are involved.