Security Siren,Keyboard Siren,Keyboard Play Siren,Keyboard Play Alarm NINGBO SANCO ELECTRONICS CO., LTD. , https://www.sancobuzzer.com The structural feature of the multi-space sound absorbing material is that there are a large number of voids and air bubbles communicating inside and outside, which can cause air vibration in the gap when the sound wave is incident thereto. Due to the viscous resistance of the air, the friction between the air and the wall of the hole causes a considerable part of the sound energy to be converted into heat energy and is consumed. In addition, when the air is adiabatically compressed, heat exchange occurs between the air and the wall of the hole, due to heat conduction. It will convert some of the sound energy into heat.
Some insulation materials, such as polystyrene and some polyvinyl chloride foams, also have a large number of air bubbles inside, but most of them are single closed and not connected to each other, so the sound absorption effect is not good. Roughing the surface of the wall, such as cementing, does not improve its permeability, so it does not increase its sound absorption coefficient.
The sound absorption frequency characteristics of the multi-space sound absorbing material are: the middle and high frequency sound absorption coefficient is large, and the low frequency sacrifice coefficient is small.