In-Situ Measurements of Surface Reflection Properties

In order to characterize surfaces with respect to their sound reflecting properties, the absorption and the scattering or diffusion coefficient can currently be measured under standardized laboratory conditions. However it is questionable whether the data from measurements performed under such laboratory conditions can be used to accurately model the actual sound field in rooms. Additionally, it is not always possible to obtain a transportable sample of a material. In-situ measurement methods can overcome these shortcomings, as they measure the desired quantities at the location where the material is installed. For this purpose, a portable setup was built that allows for a complete hemispherical measurement of the sound pressure distribution using less than 30 sensors. This contribution will present the setup together with the challenges for post-processing the acquired data. First measurement results will be presented and discussed.