A simplified method for the evaluation of flanking transmission within massive structures

Flanking transmission is the sound propagation through the lateral structures of two adjoining rooms. Evaluation of this transmission is now possible with a statistical method defined by the international standard EN 12354-1. The method can be used to calculate the acoustic performance of buildings both as a function of frequency and as single number rating (R' and R'w). When the method has to be used to calculate the acoustic properties of buildings with simple homogeneous structures, the time needed to carry out the calculation is probably too much with respect to the differences that can be found between R' and R. So the method can become tedious, especially when it isn't supported by a software or when it is used by non experts. Using the theoretical method proposed by CEN for simple homogeneous structures a new simplified tabular method has been developed which permits to obtain directly the differences between the sound reduction index R and the apparent sound reduction index R'. This method can be used in a lot of cases when a quick evaluation of the contribution of flanking transmission is needed.