Surface Tension Effect on Sound Absorption Characteristics of a Cavity-Backed Semi-Permeable Membrane

This paper describes the analysis on the characteristics of semi-permeable membrane sound absorber. The effects of membrane surface tension on the sound absorption characteristics were investigated. The characteristics of the membrane absorber was measured experimentally in terms of Sound Absorption Coefficient, α and Noise Reduction Coefficient, NRC. The membrane is made of thin, flexible, semi-permeable latex material and the tests were carried out by using impedance tube method according to ISO 10534-2 standard. The results showed that the surface tension has significant influence on the sound absorption characteristics. For the parameters used in the laboratory work, specimen with unstretched surface tension has the best absorption performance.