Sugarcane bagasse, an abundant agro-industrial residue, was engineered into bio-composite panels and selectively perforated to boost sound absorption. The influence of perforation diameter (1, 2, 3 mm) and depth (25 %, 50 %, 75 % of panel thickness) on the normal-incidence sound absorption coefficient (SAC) was quantified in an impedance tube over 200–1600 Hz. Panels with 1 mm diameter perforations penetrating 75 % of the 30 mm-thick panel achieved a peak SAC of 0.98 at 1500–1600 Hz, outperforming both non-perforated controls (SAC ≤ 0.44) and larger-hole variants. Overall, smaller diameters and deeper perforations shifted absorption toward mid–high frequencies, while large, shallow holes degraded low-frequency performance. Two-way ANOVA confirmed significant main effects of diameter (p lt; 0.01) and depth (p lt; 0.05) and their interaction on SAC. These findings demonstrate that partial micro-perforation is an efficient, low-cost route to tailor the acoustic response of bagasse-based materials, offering a sustainable alternative to agricultural-based absorbers for interior noise control and circular-economy construction.
Bakri et al. (Thu,) studied this question.