Sound barriers, primarily used for noise reduction and sound insulation along highways, expressways, elevated composite roads, and other noise sources. They are categorized into reflective sound barriers, which are purely for sound insulation, and composite sound barriers that combine sound absorption and insulation, the latter being more effective in sound insulation. Refers to wall-like structures installed alongside railways and highways to mitigate the impact of vehicle noise on nearby residents. Soundproof walls are also known as sound barriers. A facility inserted between the sound source and receiver to cause a significant additional attenuation in the propagation of sound waves, thereby reducing the noise impact in a certain area where the receiver is located, such facility is called a sound barrier. They are divided into traffic noise barriers, equipment noise attenuation soundproof barriers, industrial boundary soundproof barriers, and are extensively used on highways and expressways.