Inverse design of acoustic metamaterial sound barriers for road traffic noise control

A novel Acoustic Metamaterial Inverse Design Method (AMIDM) is proposed to achieve targeted noise reduction by linking measured noise spectra with optimized metamaterial unit cells. Utilizing a MATLAB-COMSOL co-simulation framework, an optimized barrier comprising nested Helmholtz resonators was developed to specifically target road traffic noise. Comparative analysis demonstrates that the inverse-designed structure significantly outperforms conventional uniform arrays by expanding the effective bandwidth. Simulation results revealed a broad first bandgap ranging from 400.9 to 970.7 Hz, with effective suppression of acoustic wave propagation. Impedance tube experiments confirmed significant attenuation within the same frequency band, closely matching the simulated Sound Transmission Loss (STL) response. Field tests further validated the practicality of the optimized barrier, achieving maximum sound pressure level reductions of 4.8 dB in the first bandgap and 2.9 dB in the second. These findings demonstrate that the AMIDM framework provides an efficient and generalizable approach for the inverse design of acoustic metamaterials, offering strong potential for future engineering applications in noise control.