The noise produced from internal combustion engines of automotive vehicles causes a lot of noise pollution to the environment. The harmful gases and noise from the exhaust of IC engines are prevented from free release to the environment by using AQUA silencers. Conventional aqua silencers use charcoal and steel materials for an external structure, making them heavy and sound absorption problems. This study deals with composite materials for the outer shell OF AQUA silencers made up of Glass fiber reinforced polymer and glass fiber reinforced polymer and kapok fibers. A comparative study of composite material made up of natural fiber (GFRP+kapok) and synthetic fibers, their corresponding sound absorbing properties, mechanical properties, and water absorption characteristics are tested and analyzed to arrive at optimum design of composite materials used for AQUA silencers. The sound abruption coefficient of different materials is tested and compared. However, the feasibility of the use of these composite materials commercially for AQUA silencers in the automobile industry needs to be done, and the corresponding challenges are yet to be overcome in the future, along with numerical modeling of these complex models. © 2023 Elsevier B.V., All rights reserved.