| 摘要 |
PROBLEM TO BE SOLVED: To provide a thin and lightweight structure that can reduce sounds of the low frequency to high frequency, especially can provide a high sound insulation property even in the region about 200 Hz, and is effective for cutting off the vibration of a surface material caused by a sound wave energy.SOLUTION: On both surfaces of a reflective intermediate layer 6, sound absorption layers in which a hard foam material 4 having communication air bubbles is filled into a honeycomb material 5 are disposed so as to form a symmetric structure with respect to the intermediate layer. Porous materials 3 are bonded to both surfaces of each sound absorption layer, thereby forming a panel structure. A reflective surface layer is disposed on each of both surfaces of the panel structure via an air space of a certain thickness.SELECTED DRAWING: Figure 1a |
