TRANSMISSION LOSS OF SINGLE WALLS WITH RESPECT TO THE LIMITING ANGLE OF THE INCIDENT SOUND WAVE

The transmission loss is an important property of separating building structures, which highly influences the comfort of building users. Several computational approaches are available but they differ in used input parameters which influence the precision of the prediction and the suitability of an approach for a particular situation. The angle of the sound wave incidence is a parameter which has a high impact on the resulting transmission loss. The paper briefly summarizes the theory for the calculation of the transmission loss of single leaf isotropic walls. A computational approach which enables to take into account the limiting angle of the incident sound wave below the critical frequency is presented. The development starts with the derivation of the mass law and provides a new method at the end. Proposed method for the transmission loss prediction is compared with other methods for a case of a monolithic concrete wall and a brick wall (CSN EN 12354-1, Watters's, Davy's and Sharp's method and experimental data). Differences in values obtained by different methods and measurements are discussed.