Multiple sound reflections between plane panels covered with reflection coefficients

Abstract

The sound reflection coefficient of a given material, which is measured from a sufficiently large plane of it for spherical wave incidence, has been used previously to predict the first reflection for plane, convex or concave, finite size panels covered with that material. The first reflection of such a panel can be treated as two separate waves. One is the wave from the specular reflection point and the other is a boundary wave comprised of components from the lined point sources at each edge. Here, multiple reflections between two plane panels covered with materials having reflection coefficients that may be different are approximately calculated from such separate waves as in the same treatment of rigid plane panels.