The effect of reflectors on Sound strength (G) and IACC in a fan-shape hall

The effects of various reflecting surfaces on the audience G and IACC were investigated by using open-type 1:10 scale model. In this study, the orchestra shell and three types of reflector were designed to increase the Gmid and 1-IACCE3. The reflectors were composed of triangular panels; the area of basic module was designed as 9 m 2 , based on the previous study [Nakajima et al., J. Acoust. Soc. Am. 92, 1443–1451 (1992)]. In addition, the shape of reflectors was optimized by genetic algorithm to increase G and 1-IACC. Measurements of open-type 1:10 scale model were conducted to investigate the effect of reflectors on early sounds in the auditorium. The results indicated that G and IACC were changed around 5.8 dB and 0.29, respectively, when all the reflectors were installed.