Field tests of an acoustic screen with a diffraction device

The article presents the results of field tests and the analysis of the effectiveness of a “green wall” acoustic screen with an octagonal diffraction device. Insertion loss was assessed by an indirect method. The “pre-installation” noise levels were measured at an equivalent location, next to the installed screen, where the terrain profile, reflective surfaces and ground surface did not change. An artificial, point and controlled sound source was used. In order to assess the effect of the diffraction device on the effectiveness of the screen, tests of the screen without the device were also carried out. The measurements were taken on the same day, under almost identical meteorological and acoustic conditions. In addition to experimental studies, numerical analysis was performed. Studies have shown that the diffraction device increases the effectiveness of the screen, especially at higher reception points, where the improvement was up to 6.8 dB. The results of measurements and calculations indicate a positive influence of the applied diffraction device on the effectiveness of the tested screen.