Development of ultra-broadband sound absorber based on double-layered irregular honeycomb microperforated panel

In this study, a broadband sound absorber was developed using a double-layered irregular honeycomb microperforated panel (MPP) structure and a particle swarm optimization (PSO) algorithm to address the issue of broadband sound absorption of MPPs. An acoustic impedance model of the designed sound absorber and an optimization algorithm were implemented to obtain the structural configuration parameters for quasi-perfect sound absorption. The coupling effect between the resonant elements and the optimized structural configuration parameters enabled broadband and high-efficiency sound absorption. The impedance tube experimental results demonstrated an excellent broadband sound absorption level within the range of linear acoustics, and the designed triad and tetrad structures exhibited more than 70% absorption efficiency in the range of 609-4 002 Hz and 518-5 162 Hz, respectively. This study provides a design method and insights into the design, promotion, and application of broadband sound absorbers.