Peanut Shells as an Environmentally Beneficial Sound-Absorbing Material

This study investigated the prospect of using peanut shells as an alternative and green sound-absorbing material. The sound-absorption coefficients were determined after filling impedance tubes of 30, 60, and 90 mm in height with peanut shells. The sound-absorption ability increased as the filling height increased, showing noise reduction coefficient (NRCs) of 0.23, 0.43, and 0.54 for the 30-, 60-, and 90-mm heights, respectively. In addition, for sounds greater than 2,000 Hz, the average sound-absorption coefficient of peanut shells in the 60and 90-mm heights was 0.9. In summary, peanut shells were found to have good sound-absorption properties comparable to or better than those of bamboo, sisal, jute, and wool, and this research suggests that peanut shells may be useful as an environmentally friendly sound-absorbing material.