Investigation on measurement sound field of absorption coefficient in reverberation room by numerical simulation - Relationship between room shapes and measurement results -

In this study, the relationship among the shape and volume of the reverberation room, the sound absorption coefficient of the specimen, the frequency, and the obtained measurement results of the absorption coefficient in reverberation room are investigated by time-domain finite element method. First, finite element models are created for 11 types of reverberation rooms with different room shapes and volumes, and the models are analyzed in the case that all the boundaries are rigid walls and in the case that a measurement specimen is installed on one of the boundaries. Next, the absorption coefficients in each reverberation room are calculated and relationships among the results of the absorption coefficients, the shape and volume of the room, the absorption coefficients of the specimen and the frequency are shown. As the results, it is shown that relationship between absorption coefficient in reverberation room and absorption coefficient of specimen was varied by the absorption coefficient of the specimen and frequency more than room volume in heptahedral irregularly shaped reverberation room.