Sound-absorbing materials can make any material absorb sound, but the degree of absorption is very different. Most of them are loose and porous materials, such as slag wool, blankets, etc., and their sound absorption mechanism is that sound waves go deep into the pores of the material. And the pores are mostly open holes that communicate with each other internally, which are subjected to friction and viscous resistance of air molecules, as well as mechanical vibration of fine fibers, so that sound energy is converted into heat energy.