Road Traffic Noise Prediction Model 'ASJ RTN-Model 2018' Proposed by The Acoustical Society of Japan - Part 3: Calculation model of sound propagation

摘要

As the third part of "ASJ RTN-Model 2018", calculation model of sound propagation is presented. This model is basically developed as a practical calculation model based on Geometrical Acoustics. The calculation equations in this model are defined on the basis of experimental or numerical analysis data. The overall values of the A-weighted sound pressure level of noise propagating from a vehicle are directly calculated by considering the frequency characteristics of vehicle noise. This calculation model consists of shielding effects by several type barriers, excess attenuation due to ground surface, atmospheric absorption effect, sound reflection and meteorological effect. Based on newly obtained knowledge, several improvements were made on the calculation method to develop the model.