A noise barrier is a physical product or component that is placed near high noise areas such as highways, airports, railway tracks etc. Fundamentally, noise barriers are of two major types –
1. Metallic Noise/Sound Barrier: made up of material like steel, aluminium or stainless steel.
2. Polycarbonate/PMMA Noise Barrier: made of material like polycarbonate and acrylic.
Be it a metallic noise barrier or a polycarbonate noise barrier, the basic principle behind the working of a noise barrier can further be divided into two categories namely –
a) Noise Insulation – a technique where a noise insulating material is used to prevent noise transmission.
b) Noise Attenuation – a technique where a noise absorbing material is used to prevent noise transmission.