Noise Barrier as an Option to Reduce Road Traffic Noise from Highways in Klang Valley, Malaysia

A noise barrier can be defined as an obstacle to sound propagation between the sound source and the listener, where the noise propagates either above or around the barrier. In Malaysia, there is a lack of literature regarding noise barriers, including design of noise barriers that have been erected. This study investigates the design of existing noise barriers; vegetation, masonry concrete hollow block and panel concrete at three urban residential areas in Klang Valley region. The finding in this study indicates that noise barriers of masonry concrete hollow block and concrete panel height are 4.6 m and 2.8 m, respectively. These height of noise barriers exceeded line of sight at sampling point with 1.5 m of microphone height from the ground. This may imply diffraction of sound wave on top of the noise barriers. Apart from that, both concrete hollow block and panel concrete noise barriers were perforated in each panel and block to absorb some energy of sound and consequently helps to reduce noise from highways.