Stainless steel silencers refer to devices that can reduce noise in air ducts with noise propagation, utilizing pipe sections lined with sound-absorbing material, elbows, or pipes with sudden changes in cross-sectional area and other discontinuities in acoustic impedance to attenuate or reflect back the noise within the pipes. The former is called a resistive silencer, and the latter is called a reactive silencer; there are also impedance composite silencers. There are many types of silencers, but in terms of their noise reduction mechanisms, they can be primarily categorized into six types: resistive silencers, reactive silencers, impedance composite silencers, micro-perforated plate silencers, small-hole silencers, and active silencers.