Acoustic barriers, primarily used for noise reduction on highways, expressways, elevated composite roads, and other noise sources. They are divided into reflective acoustic barriers for pure sound insulation and composite acoustic barriers that combine absorption and insulation, with the latter being a more effective sound insulation method. These refer to wall-like structures installed alongside railways and highways to mitigate the impact of traffic noise on nearby residents. Sound insulation walls are also known as acoustic barriers. An acoustic barrier is a facility inserted between the sound source and receiver to significantly increase the additional attenuation of sound wave propagation, thereby reducing the noise impact in a certain area where the receiver is located. These are categorized into traffic noise insulation barriers, equipment noise attenuation insulation barriers, industrial boundary noise insulation barriers, and they are commonly used on highways and expressways.