Type of Noise Reduction Material

1. Porous Material
   1. Function: Friction
   2. Product: cementicious, fibrous
   3. 適用性: High Frequency
   4. Cost: Low

   　

2. 版、膜 Material
   1. Function: Vibration
   2. Product: Gypsum board, Fiber board
   3. 適用性: Low Frequency
   4. Cost: Medium

   　

3. Resonance Material
   1. Function: Resonance
   2. Product: 打孔版、共振吸音器
   3. 適用性: Low、Medium Frequency
   4. Cost: High