Abstract
The analysis of Jones for scattering of a plane wave by three equidistant parallel half planes is extended to the case of a line source. It is found that if the source is shifted to a large distance these results differ from those of Jones by a multiplicative factor. Subsequently, the scattering due to a point source is examined using the results obtained for a line source excitation. The two problems are discussed when the acoustic medium is still as well as when convection is present.