Efficiency of edge-modified noise barriers: Intrinsic efficiency determination of practical products and prediction of the diffracted sound field

Abstract

In this paper, the noise shielding efficiency of barriers with an acoustic device mounted on their top edge for reducing sound diffraction is described. The authors have already found that the intrinsic efficiency of the device, which is related to the noise-reducing mechanisms, is a function of the angles of the source and receiver but independent of their radii. In the present paper, a novel procedure based on the previous finding is applied to determine the acoustical efficiencies of practical edge-modifying products in the near field, and the results are utilized in calculations to predict sound diffraction behind the edge-modified barriers in the far field. It is proved that the novel method provides an accurate prediction.