Sound transmission loss of double layer impervious membranes with an internal microperforated membrane

Abstract

Double layer impervious membranes are commonly used as building materials. This paper provides results of experiments that show the effect on sound transmission loss associated with the incorporation of a microperforated membrane (MPM) layer. Four types of MPMs with different perforation ratios are considered inserted between the two impervious membranes and the effects of the perforation ratio on the sound transmission loss of the combined system are investigated. The measurements employ two reverberation chambers and are conducted in accordance with the AS/NZS ISO 717.1 standard (2004). The test results show that an internal MPM is able to significantly increase the sound insulation of double layer impervious membranes. This double layer structure with an internal MPM is suitable for lightweight sound barriers and is promising and worthy of further study. Copyright © (2013) by the Australian Acoustical Society.