Absorbent parallel noise barriers in urban environments

Theoretical and experimental studies are presented for the acoustic performance of parallel absorbent noise barriers in the presence of one or two parallel façade surfaces. A modified ray model has been developed to calculate the sound fields in these complex urban environments. The ray model has been validated by comparing with scale-model experiments and a wave-based computationally intensive numerical scheme. The barrier insertion loss is shown to be dependent on the source/receiver geometry, the acoustical property of the absorbent materials and the configuration of parallel noise barriers.