Sound Absorption Capability of Medicine Herb Residues Mat

This study investigated the sound-absorbing properties of herbal medicine waste (HMW) as a promising eco-friendly material for sound absorption. The authors examined the sound absorption coefficient by filling impedance tubes with varying heights of HMW (4 cm, 6 cm, 8 cm, and 10 cm). The results revealed that at a filling height of 4 cm, the optimal sound absorption frequency was found to be 1416 Hz, with a sound absorption coefficient of 0.999. Similarly, at a filling height of 12 cm, the optimal sound absorption coefficient was 0.965 at 456 Hz. It was observed that the sound-absorbing performance at lower frequencies improved as the thickness of the sound-absorbing material increased. Based on the standards established in KS F 3503, HMW would receive a sound absorption grade of 0.5M to 0.7M, depending on the filling height. In conclusion, HMW showed excellent potential as a sound-absorbing material, and the results of our testing showed that it can be used as an alternative to synthetic fibers.