Transmission loss of triple partitions at low frequencies

Abstract Sound transmission through triple partitions has been investigated at low frequencies, where an essential role is played by the resonances of the partition, modelled as a system of masses (plates) and springs (air gaps). It was found that the transmission loss of a triple partition (in a symmetric case) may be much less than of a double one of the same mass per unit area. The theoretical results are in good agreement with laboratory measurements of transmission loss of double-spaced multiple glass units, and with experimental data of other authors.