MEASUREMENT OF SOUND REFLECTION USING THE SOPRA METHOD

Paper in proceeding, 2023

Within the Industrial PhD project Acoustical Planning of Complex Traffic Environments, it is studied whether it would be possible to change the materials or the design of the surfaces of the infrastructure to reduce the sound reflections and decrease the noise levels from road traffic. Of critical significance for the possibility of taking such potentially noise reducing measures, is the ability to calculate the acoustic effects of the surfaces reliably. This requires sound absorption/reflection data of surfaces and materials. Existing data are usually acquired under diffuse sound field conditions in laboratories, but measurements of road noise barriers have shown that absorbing materials often function differently under direct sound field conditions. The required data must thus be obtained by measurements in-situ. Several measurement methods have been considered, e.g. the European standard method for measuring sound reflection of road noise barriers in direct sound field, the EN 1793-5. However, when a quicker version of the EN 1793-5, the SOPRA method, was presented in June 2022 it was decided to try it for measuring the sound reflection of various surfaces in the road infrastructure (road pavements excluded). This paper presents the preparation, execution and results from the test measurements with the SOPRA method.