Predicted and Measured Low Frequency Response of Small Rooms

The sound level difference of party walls at low frequencies [25–200 Hz] has been shown to be strongly dependent on the modal characteristics of the sound fields of the separated rooms. The modal characteristics can be modelled by numerical methods and a Finite Element Method has been selected to model sound transmission between adjacent rooms separated by a party wall. The numerical eigenfrequencies were compared with the theoretical eigenfrequencies to select a mesh model for which the eigenfrequencies are processed within an acceptable error range.

As a prelude to the study of sound transmission between dwellings, the simulation of one single room, modelled with the selected mesh model, was validated by predicting the frequency response and comparing values with measured frequency response of a 1:4 scale room model. Results show promising agreement and establish the reliability of the work.