Effect of coverage on the acoustic performance of selected porous and fibrous materials

Acoustic structures based on fibre slabs must be protected from mechanical damage. It is also important to protect the user from dust, the source of which may be the fibrous material (rock or glass wool). In individually manufactured panels, due to special aesthetic or functional qualities, it is necessary to select alternative coverings to those used in publicly available panels, whence arose the need to analyse different materials that could be used for coverings and determine their effect on the acoustic properties of the base material. The study was carried out analytically, numerically, and experimentally on two different porous materials and one fibrous material. Eleven different coverings were analysed, including four impermeable ones. The results made it possible to demonstrate the magnitude of the effect of the covering material on the sound absorption coefficient of the base material and to develop recommendations for the selection of the covering material depending on the base material.