Noise barriers with diffraction-reducing devices on top edge: Propagation prediction applying intrinsic efficiencies determined by impulse-response measurement

摘要

This paper describes the noise-shielding efficiency of barriers with an acoustic device mounted on their top edge to reduce sound diffraction. Effect of the edge device consists of two components: increase of barrier thickness and the acoustical mechanism such as absorption or interference. The latter effect is determined by impulse-response measurement around the barrier edge, and determined results are substituted to propagation prediction of sound diffraction behind the edge-modified barrier. The proposed method is applied to predict road traffic noise behind edge-modified barriers in two actual sites. It is indicated that the LAeq behind the barrier is predicted almost precisely in comparison with roadside noise measurement.