Validation of the pyramid tracing algorithm for sound propagation outdoors: Comparison with experimental measurements and with the ISO-DIS 9613 standards

The accuracy of numerical provisions of the sound propagation outdoors made with the newly developed pyramid tracing algorithm, was tested using a directive loudspeaker as the sound source. The pyramid tracing code was compared against experimental measurements and with the ISO-DIS 9613 standards. Both the experimental and numerical data were used to build graphical plots, enabling a direct comparison of the results: they show that the capability of accurately modeling the source directivity produces generally a better estimate using the pyramid tracing algorithm, but the shielding effects and excess attenuation are more accurately modeled by the ISO 9613 code