Effect of sample size on measurement of the absorption by seats

This study deals with measurements of the sound absorption by seats which are one of the important parameters in the early design stage in auditorium. In this study, the effects of sample size on measurement of the sound absorption by seats are investigated to define an optimum range of sample size for obtaining reliable measurement results. In the measurements, the absorption coefficients of unoccupied seats at a scale of 1/16 are measured in a 1/5 scale-model of the reverberation chamber based on ISO 354. Various seating blocks having 9 different P/A (perimeter/area of the sample) values ranged from 0.4 to 1.37 m^-1 were measured to extrapolate to the absorption coefficients of the larger seating blocks found in a real hall. The predicted results from reverberation chamber measurements were then compared to the measured values in a 1/16 scale-model of the real hall for the validation of this method. The present results show good agreement between values obtained from the hall measurements and those predicted from reverberation chamber measurements.