A study of suitable noise barrier materials for KTM commuter system at the residential area between Shah Alam to Bukit Badak route

Noise emitted from the running train affecting surrounding area as the development of the railroad system increase nowadays. Noise reduction becomes important in reducing negative impact to the surrounding environment. The purpose of this study is to determine the maximum level of the noise that produce by the ktm commuter using the Sound Level Meter (SLM), to study the suitable type and test the reliability in terms of the noise absorption of the material used for the noise barrier due to the maximum level of the noise, and to propose the suitable design of the noise barrier based on the material that have the highest absorption of the noise in terms of its height. Maximum noise level emitted from Shah Alam KTM Commuter Station to Bukit Badak KTM Commuter Station determined using the instrument called Sound Level Meter (SLM). The instrument placed at three distance to the center of the track which at 15 metre, 20 metre and 25 metre. Absorption Coefficient and transmission loss value determined using Impedance Tube Kit for Rockwool, Polyethylene (PE) foam and Polyurethane (PU) foam. Noise barrier height is then calculated using Path Length Difference Method. The results of fieldwork shows the average maximum level of noise that emitted from KTM Commuter train was 73.90 dB to 77.60 dB which over the maximum limit stated by WHO which is 65 dB. Rockwool was the suitable material for the noise barrier because of the absorption coefficient of Rockwool was 0.943 that is nearly to 1 which is fully absorption. The average absorption coefficient of PE foam was 0.627 also considered high compared to PU foam reading which 0.346, nearly to 0 which considered fully reflection. The purposed barrier height was 4.01 metre for Rockwool material