School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China

Abstract

Low-frequency sound waves exhibit a long wavelength and a difficult attenuation during the propagation process. Moreover, they can easily resonate with human organs, which can have a serious impact on human health. Traditional sound-absorbing materials are insufficient in controlling the low-frequency sound waves; thus, a new way to solve the noise pollution issue is summarized through the development of acoustic metamaterials. This study summarizes the research status of acoustic metamaterials and focuses on specific methods and the practical effects of several typical sound-absorbing metamaterial structures to achieve low-frequency noise reduction through structural design, including membrane-type and thin plate-type acoustic metamaterials, Helmholtz-like sound-absorbing metamaterials, and composite sound-absorbing metamaterials. Finally, combined with the current deficiencies in the design and the practical process of sound-absorbing metamaterials, the existing problems and the future research directions in the field of sound-absorbing metamaterials are summarized under this framework. It provides a reference for the research and practical applications of the sound-absorbing structure design and related performance.