Gene-modified acoustic metamaterials for improving the low-frequency broadband noise reduction performance of sound barriers for transportation buildings

To improve the noise reduction capability of sound barriers for existing transportation buildings, a gene-modified acoustic metamaterial is proposed for noise reduction into the sound barriers. Simulation results show that the sound absorption coefficient of metamaterials sound barrier (MSB) is more than 0.85 in the range of 800Hz-8kHz, experiencing significant improvement across both low and medium acoustic frequency ranges compared with the existing sound barriers., wherein it is found that the impedance-matching effect is the key to achieving near-perfect sound absorption. The simulation results of sound absorption coefficient and sound transmission loss match well with experiments, where it is found that the sound insulation performance can reach higher than 30.0 dB at frequencies above 200 Hz from the sound transmission loss curves. Experiments demonstrate that the installation of metamaterial sound barriers (MSBs) can reduce ambient traffic noise by 7.3 dB. This research is expected to bring new technical support for reducing urban traffic noise and improving the indoor living environment.