A microperforated panel (MPP), which is widely known as one of the most promising alternatives of the next-generation sound absorbers, is typically used with a rigid-back wall with an air-cavity. However, a multiple-leaf MPP space absorber, which does not have any backing structure, double-leaf MPP space absorber (DLMPP) and triple-leaf MPP space absorber (TLMPP) is proposed. However, these are panel-like structure which are limited to where they can be used. In order to develop an MPP space

more »

... orber that can be used in more various situations, a trial production of a cylindrical MPP space sound absorber (CMSA) is made with an MPP shaped into a cylindrical. The sound absorption characteristics of a CMSA are measured in a reverberation chamber. As a result, although the absorption coefficient is not very high, a CMSA shows sound absorption characteristics similar to a DLMPP and TLMPP: a resonance peak by a Helmholtz resonator and an additional low frequency absorption by its acoustic permeability appear. The results suggest that a CMSA can be used as a space sound absorber in practical situations. V C 2012 Institute of Noise Control Engineering.