 This study explores natural fiber-based hybrid composites as possible structural materials and investigates their sound insulation properties using an impedance tube with four microphones. Hybrid biocomposites were prepared with chopped and randomly oriented coir and banana fibers, using polypropylene as a matrix and compression molding for fabrication. The ratio of both fibers was maintained at one to one. Fiber loading and arrangement significantly improved sound insulation property, with experimental results showing that increase in fiber loading up to a certain limit enhanced the sound insulation performance. The study discusses customizing sound insulation performance by structural parameters such as volume fraction, dispersion, ratio, and placement of fibers without changing raw materials. This article was authored by Vikas Kumar Singh and Samrat Mukhopadhai.