Using Statistical Energy Analysis to predict sound insulation in buildings

Sound insulation in the field is determined by both direct and flanking transmission; hence a prediction model such as Statistical Energy Analysis (SEA) is useful at the design stage to determine the overall transmission. This paper gives an overview of classical SEA models which are commonly used to predict airborne and impact sound insulation. Such models sometimes need to incorporate data from measurements or deterministic models (e.g. finite element methods) to give accurate predictions. For example, this occurs when building components, or the coupling/connections between them, are too complex to model with simple idealizations of beams, plates and springs. This is sometimes considered in the low-frequency range because heavyweight walls and floors often have low modal density and low modal overlap which increases the uncertainty in coupling loss factors predicted using wave theory. In this paper, experimental and numerical examples are used to illustrate aspects relating to the inclusion of laboratory measurements in SEA models. Whilst classical SEA gives predictions of steady-state sound and vibration (i.e. Leq values) it is also useful to be able to predict Fast time-weighted sound pressure levels inside buildings. Hence examples are given to show that when the principles of classical SEA are applied in short–time periods using Transient SEA (TSEA) it is possible to predict Lp,Fmax from transients such as footsteps on heavyweight floors.