Design and Optimization of a Resonant Type Acoustic Meta-Material for Sound Attenuation

Considering the fact that most conventional acoustic materials have reached their limit in terms of performance, it is important to find new ways to attenuate sound. This study describes the design and optimization of the sound absorption and sound insulation of an Acoustic Meta-Material (AMM) based on embedding acoustic resonators in a porous material. Previous works have already addressed this kind of AMM, mostly using simulations and tests in impedance tubes. This work develops and tests the studied AMM at medium-scale (60 x 60 cm², tested in acoustic cabin). The proposed solutions are specifically used to attenuate low frequency noise are easily manufacturable. Theoretical and experimental investigations are conducted to optimize and validate the concepts under realistic density and volume constraints. Starting with analytical solutions, using transfer matrix method, and numerical simulations, using FEM/BEM module of NOVA software, various concepts are optimized in terms of sound absorption and sound transmission. Optimized concepts are fabricated and tested in a medium-scale acoustic test chamber to demonstrate their augmented acoustic insulation performance.