Microperforated panel absorbers (MPPA) are acoustic absorbers that consists of a perforated panel fitted in front of a rigid wall and air cavity. The absorption frequency range of MPPA is limited in the vicinity of the resonance frequencies due to the sound absorption mechanism. There have been researches to widen the absorption frequency range of MPPA, however, the approaches increase the volume of the whole absorber. It is important to minimize the volume of the absorber while widening the absorption frequency range. In this study, the trade-off between the bandwidth of the sound absorption and the volume of MPPA is clarified through the multi-objective design optimization by sequential approximate optimization (SAO) using radial basis function (RBF) network. The normal sound absorption coefficient of MPPA is evaluated by the transfer matrix method. The effect of the number of layers was investigated by optimizing the structure of 2 to 4 layers MPPA.
Tabuchi et al. (Wed,) studied this question.