Optimization of STL sound transmission loss of tris(dimethylaminopropyl)hexahydrotriazine in sound-absorbing cotton of elevator car Preface: The “Invisible Cloak” of the Sound In modern society, elevators have become an indispensable part of our daily lives. Whether it is high-rise office buildings, luxury apartments or hospital shopping malls, elevators are important links connecting different floors. However, as...