Metamaterial acoustic barriers for traffic noise control in urban zones

The study focuses on acoustic metamaterials—structures designed to control how sound waves travel—by using geometric features that create resonance and periodic behavior. To address traffic noise in urban areas, the authors develop a methodology using small-scale prototypes. They build a 1:10 scale 3-D model using PVC square bars, with configurations that either include or exclude porous polyethylene layers. Sound passing through the different barrier configurations is measured with a Brüel & Kjær Class 1 Sound Level Meter, and the insertion loss is analyzed in the frequency domain. The results indicate that the metamaterial prototypes can effectively control sound propagation, and that adding the polyethylene layer enhances noise absorption across a broad frequency range.