Abstract: Noise reducing screen disposed between an elongated noise source formed by a motorway or a railway and a building located along one side of this noise source and to be shielded therefrom. This noise reducing screen comprises a continuous wall portion having a whole length 2d, built up between the elongated noise source and the building on both sides of a perpendicular drawn from the building point the most remote from the noise source and located at a distance D therefrom to the elongated noise source and a plurality of variably spaced apart posts aligned with said wall portion, these posts having a length a and a width b repectively parallel and perpendicular to the elongated source, the spacing between the n.sup.th and (n-1).sup.th post being at most equal todp.sup.n + (a-d)p.sup.n-1 with n.ltoreq.2 (and dp or n=1)Where p is the ratio D/(D-b)It results from this spacing that all rectilinear noise propagation paths from the noise source to the building are intercepted by the posts.