Reciprocity and the Prediction of the Apparent Sound Reduction Index for Lightweight Structures According to EN12354

Abstract

EN12354 makes use of reciprocity to cancel the radiation efficiency terms from the equations used to predict the apparent sound reduction index. The use of reciprocity works well for the application of EN12354 to massive, concrete structures with diffuse wave fields and with critical frequencies below the frequency range of interest. However, lightweight constructions may have critical frequencies above the frequency range of interest and may not support diffuse wave fields. The use of reciprocity for application to lightweight structures may introduce errors into the predictions. This study investigates the uncertainty introduced into the predictions of the apparent sound reduction index of lightweight constructions due to the use of reciprocity.