On the use of scaled models in building acoustics

Abstract

Experimental studies of physical effects in building acoustics are usually time consuming and expensive. This is mainly caused by the building costs but also by the experimental effort. It is thus desirable to have another method for the investigation of basic effects in building acoustics. Building acoustic problems are characterized by the interaction between airborne and structure‐borne sound fields. It is therefore possible to use scaled models when both sound fields are treated correctly. This means that the wavelengths in the airborne and in the structure‐borne sound fields have to be scaled in the same way. With a scaling factor of typically 1:8, the costs can be reduced drastically and nearly all model parameters can be changed separately. Due to these advantages, this technique is used at PTB's building acoustics group. This contribution gives an overview on the physical background of scaled models, reports on validation experiments and on several applications e.g. investigations of the influence of temperature and static pressure, damping effects, geometry influence on the sound insulation of walls, the measurement of the flanking transmission of walls and the measurement of suspended ceilings.