To provide a sound absorbing structure excellent in a sound absorbing coefficient for road traffic noises.
This sound absorbing structure has a layer of glass wool with a small bulk density, placed on the sound source side as a sound absorber, and a layer of glass wool with a greater bulk density which is stacked behind the former layer. The bulk densities of both of the layers of glass wool are within the range from 16 to 32 kg/m3, the ratio of the bulk densities is in the range of 1:1.3 to 2), the total thickness of the layers of glass wool are 100 to 200 mm, and if necessary an air layer is formed behind the layer of glass wool of greater bulk density. The figure shows a sound absorbing coefficient weighted with road traffic noises when a layer of glass wool of 16 kg/m3 is combined with a layer of glass wool of 32 kg/m3, and in a certain range the sound absorbing coefficient is higher than that of a case where one layer is used.
SUGIMOTO RIE
TANAKA TOSHIMITSU
HAYASHI NOBUTERU
IWAI KENJI
TANIMOTO HIROSHI
