Air-Borne Sound Insulation of Single Walls at Low Frequencies: A Discussion on the Influence of Boundary and Mounting Conditions

Abstract

A theoretical analysis of the air-borne sound transmission through a single wall at low frequencies is presented. The wall is assumed to be surrounded by orthogonally mounted partitions. The results are compared with those presented previously for a wall mounted in a baffle. The comparison shows that the presence of the orthogonal partitions can substantially increase the transmission due to the forced response at frequencies around and below the critical frequency. The magnitude of this effect depends on how the wall is mounted to surrounding constructions; it can be large for certain cases. The analysis also shows that the transmission due to the resonant response increases by 6 dB at frequencies below the critical frequency in the region where the edge radiators are predominant.