Abstract
Although the vibration effect of micro-perforated panels (MPPs) in passive sound absorption systems has been considered in some studies, research into active systems remains to be accomplished. In this paper, theoretical and experimental studies of hybrid systems using finite flexible MPPs are presented. The impedance of the flexible MPP is derived using the modal analysis solution of the classical plate equation. Then absorption coefficients are predicted based on an electro-acoustic equivalent circuit model. A study of the absorption mechanism of the hybrid system shows that panel vibration can degrade the Helmholtz-resonance absorption performance and bring out panel-type absorption, especially increasing the cavity absorption in systems using impedance-matching conditions. Theoretical results show good agreement with the experiments. It can be seen that flexible the MPP has the potential to dissipate more energy and can be utilized to improve the absorption performance of the hybrid system by appropriately selecting parameters.