Propagation of a spherical wave near a plane boundary with a complex impedance

Abstract

An analysis, using complex angles of incidence as the variable in a steepest descents integration, is made of the propagation of sound from a point source over a locally reacting complex impedance boundary. The integration process contains more terms than are normally used in the analysis, and the solution is valid over a large range of horizontal distances. Conditions for the existence of surface waves are discussed in some detail. A comparison is made of measured and calculated values of pressure on the boundary. [Prediction of the sound level produced by a source or a series of sources in community noise situations is mentioned.].