Impulse response of the early reflections in an auditorium

Abstract

The practical calculation of the first reflections from elements comprising the boundaries of an auditorium (such as rigid plane panels, rigid curved panels, and panels having reflection coefficients other than unity) will be reviewed. Measured reflection coefficients of porous layers and auditorium seats at grazing incidence will be shown, concentrating on the time domain. Next, multiple reflections between two plane panels, two rigid convex panels, two plane panels with reflection coefficients different from unity, and those inside a rigid concave panel are calculated, based on the calculation of the first reflections mentioned above. These results are in good agreement with those measured. Finally, the calculated pulse response of the early reflections in a scale model auditorium, which is the convolution of the calculated impulse response and a direct sound generated by a point source, will be compared with the measured one. Comparison will also be made of their frequency characteristics.