Research Progress on Structure Design of Sound Absorption and Noise Reduction Based on Metamaterials

Noise pollution is an important environmental problem. It is always a challenging subject to study how to design sound-absorbing structures to reduce noise in the environment. Compared with the traditional material，metamaterials have attracted wide attention due to their excellent advantage in the low-frequency sound absorption. In this paper，two major mechanisms，i. e.，the acoustic viscosity theory and the heat conduction theory，of acoustic absorption are introduced. Next，the basic research methods of sound absorption structures are introduced，including the impedance analysis theory，the numerical calculation method， and the experimental technique. The impedance analysis theory includes the impedance matching theory and the complex frequency plane. Then，according to the current design and research status of sound absorption structures，this paper presents relevant works， introducing the research progress of design based on metamaterials， and analyzing the practical application and possible development direction. Finally， the absorber based on metamaterials is summarized from structure design，working frequency，structural size and absorber performance， and the challenges in practical application and working condition are analyzed. © 2022 Science Press. All rights reserved.