This study evaluates the acoustic properties of water hyacinth fiber composites, a notorious invasive species, focusing on their effectiveness as sound absorbers and insulators. By converting this abundant weed into bio-based materials, the research presents a promising eco-friendly alternative for acoustic applications. By examining a range of densities from 118 to 282 kg/m³, the study identifies how density impacts the Sound Absorption Coefficient (SAC) and Transmission Loss (TL). Notably, the sample with a density of 118 kg/m³ exhibited the highest Sound Absorption Average (SAA) at 0.63, while the densest sample at 282 kg/m³ achieved the highest Transmission Loss Average (TLA) at 32.5 dB, illustrating a direct correlation between increased density and enhanced TL, alongside a decrease in SAC. Statistical models obtained from the analysis of variance (ANOVA), semi-phenomenological model (Johnson-Champoux-Allard (JCA) model), and empirical model (based on the Delany-Bazley model) have been developed to predict the sound absorption and sound insulation performance of water hyacinth. These models demonstrate average errors of 0.0300, 0.0346, and 0.0377, respectively, significantly outperforming established models like the Delany-Bazley and Garai-Pompoli models in predicting the sound absorption average of water hyacinth bio-based composites. These models can be used to predict the acoustic properties of the composites, assisting in tailoring the composites to match specific applications. This approach leverages the natural abundance of water hyacinth to develop environmentally friendly acoustic materials, offering a sustainable solution to invasive species management and material development.