Investigation of possible vegetation for a natural sound barrier

Abstract

Noise pollution has been identified as the third most hazardous type of pollution in the world. Vegetation was used for experiments recently to check the effectiveness as a sound barrier. This research includes a qualitative analysis of natural vegetation fences to identify the parameters contributing to noise attenuation and its effectiveness. A-Weighted noise levels were measured for frequencies ranging 125 Hz to 16 kHz upto 9m from barrier using a sound level meter with 1:1 octave band. Same test was carried out for artificial walls to compare the effectiveness of vegetation barriers. The identified parameters contributing to noise attenuation were thickness of the barrier, leaf density (primary) and height (secondary). According to results, a vegetation barrier of considerable thickness, height and dense leaves can achieve the effect of a low height artificial barrier. Although vegetation attenuate noise, it seems to be not enough to reduce the current noise levels below the level that can be borne without annoyance.