A study on the acoustical absorption behavior of coir fiber using miki model

Abstract

Sound absorption capacity of natural coir fiber collected from coconut husk has been explored and predicted using Miki's empirical model. Experiments are conducted in impedance tube to validate the analytical outcomes for three samples having different thickness backed with and without air gap. Results show that the empirical model can estimate the absorption coefficient of coir fiber favourably well and shows higher accuracy than the Delany-Bazley model. Discrepancies between the predicted and measured absorption coefficient is very low although some inevitable irregularities is observed in the peak positions. However, presented Miki model can evaluate the overall acoustic behavior of coir fiber. This approach can be considered as a very simple and preliminary analytical solution for coir fiber acoustical characterization without considering several physical parameters of porous media. In addition, as a result, no complicated measuring procedure has to be followed to initiate the preliminary study for this material.