Prediction of the acoustic field due to a point source over a porous layer (L).

Comparisons are performed between the results of a simple classic formulation for the acoustic field created by a point source above a porous layer and an exact description. A semi-infinite layer and layers of finite thickness are considered. It is shown that for layers of finite thickness and small flow resistivity the use of the classic formulation can lead to large errors close to grazing incidence.