Taking into account the temporary and spectral structure of the sound energy for the characterization of the annoyance generated by the road and railway traffic

Abstract

As several authors have indicated, the massive transport systems represent one of the most important environmental externalities. The big road and railway axis generate a high degree of annoyance in the adjacent population, due, among other things, to the large amount of generated sound pollution. The above mentioned sound pollution possesses a series of temporary and spectral characteristics, as well as of emitted energy level, which forces us to consider more factors besides of the LAeqdescriptor, to evaluate the impact on the affected population. In turn, due to the fact that the circulation characteristics of the road and railway traffic are totally different, it suits to study separately the above mentioned situations and characterize the generated sound impact. For it, in this work we carried out an analysis of both the temporary structure, (the variability level of the received sound energy, the crest factor of the sign, etc), and the spectral structure, through factors such as tonal components, spectral variability of the sound energy, percentage of sound energy in critical frequencies, etc. The proposed factors are to be seen as a complement to the average level of exposure level of the sound energy for the evaluation of the sound impact generated by big roads and railway axis on the exposed population.