Barrier-wall attenuation with a finite-sized source

Abstract

The computed attenuation afforded by an infinitely long barrier wall between a point source and a distant receiver has been extended to a source of finite size by considering it as a rectangular array of small equal closely spaced incoherent sub-sources. While one axis of the array is assumed to be vertical, it may have any angular orientation relative to the receiver and to the axis of the wall. If the source and wall are parallel, the high-frequency attenuation drops by 3 Db when the source-to-barrier spacing is doubled, and varies as 10 log (1 − h/H), where h is the source height and H is the height of the barrier.