Abstract : In this research, natural fibers are used as composite materials as sound absorbers because they can reduce noise. Sound absorbers from natural fibers can reduce noise. It consists of a combination of coconut fiber and banana midrib as a filler and PVAC glue as a matrix. The variations of ratio of the coconut fiber and banana’s mid ribs are 1:1, 2:1, 1:2. To bind the material, PVAc glue was implemented, with its thickness ratio= 2 mm, 3 mm, and 4 mm. The sound-absorbing coefficient value refers to the ISO 11654:1997 standard. The final result shows the value of the sound absorption coefficient= 0.15 on a ratio of 1:1 with a thickness variation of 3mm, 4mm. It is categorized in C-grade. At a fiber ratio of 2:1, with a thickness of 2mm, it is categorized as E-grade. In the ratio of 1:2 fiber with a thickness of 2mm is categorized in E-grade, and 4mm is categorized in D-grade.