Validation of calculation methods for sound propagation outdoors

摘要

Different calculation methods exist that include meteorological and ground effects. It isrnimportant to know how accurate these methods are and if the loss in precision andrntransparency is justified by an adequate improvement if such effects shall be predicted.rnMeasurements have been undertaken that can be used to check the uncertainties and tornevaluate and rank the deviations between calculated and measured levels.rnIn the frame of the European CNOSSOS-EU project it is planned to compare the methodsrnISO 9613-2, NMPB 2008, Harmonoise and some others. The noise levels produced by arnuniformly radiating sound source are measured at receivers at different distances. Thernsame scenario is modeled and the levels are calculated with these above mentioned methods.rnThe comparison of calculated and measured levels is an effective method to qualify arncalculation method and to optimize the selection of default parameters to be used.