The development of sound absorbing materials using natural bamboo fibers and their acoustic properties

摘要

An acoustic material has been newly developed from the viewpoint of environmentalprotection. For this purpose, we used a natural resource, bamboo fiber, to manufacture soundabsorbing material. The normal incidence sound absorption coefficient of bamboo fibermaterial was measured at the influences of thickness, air space, apparent density and thebamboo fiber diameter using an impedance tube. In addition, the characteristic impedance andthe propagation constant of the materials were measured. The contour lines of the soundabsorption coefficient by calculation were pictured as the thickness and the air space ofmaterial respective density. We tried to find the best combination of samples of differentdensities for the improvement of sound absorption effects with the whole weight of thematerial constant. The sound absorption coefficient effect can be improved by combinationfelt, board and air space. Consequently, fundamental design criteria have been confirmed usingthe newly developed bamboo fiber material for sound absorption.