Normal incidence sound absorption coefficient measurement using sound intensity technique: An accuracy investigation

Abstract

Sound absorption data are required in specifying and proposing the correct materials for room acoustic treatment. However, there are instances where noncommon materials such as direct piercing carved wood panels (dpcwps) are used without sound absorption data. Sound absorption measurements obtained using an impedance tube and reverberation chamber are not accurate for dpcwp. This is primarily because the wall backing the dpcwp during the measurements constitutes the carved surface, which does not exist in actual installation. Therefore, an alternative measurement technique using a sound intensity measurement technique is more appropriate for dpcwp. This paper focuses on experimental methodology where various aspects need to be taken into consideration to achieve accurate results. Various criteria affecting measurement instruments’ capabilities and other factors affecting sound intensity measurement accuracy will be discussed. Sound absorption measurement was conducted on three different perforation panels which resemble dpcwp and it was found that the sound absorption measured with a deviation from an average value of −5.59% to 5.95% can be achieved, and is particularly accurate.