With the progress of society and the development of cities, people's living standards continue to improve, and urban transportation has become a more closely related issue to us. The construction of a large number of highways and the opening of urban light rail have brought great convenience to our travel, but at the same time, residents living near these highways and light rail are enduring the impact of traffic noise.

In subway construction and operation, the sound environment has always been an important indicator of whether the system can meet passenger comfort and the health of residents around the station. During the normal operation of the subway, various types of wind turbines can form varying degrees of sound sources, with noise levels typically ranging from 80-110 decibels, making them the main source of noise within the station. The subway operating environment is relatively humid and dusty, and there are relatively few professional maintenance personnel, so the metal shell matrix muffler is one of the essential tools for reducing noise.