It is of interest to investigate the sound propagation of long enclosures with a vertical/inclined branch, since there may exist some branches inside the long enclosures in practical applications, such as in high-speed railway tunnels. However, much research on sound propagation of long enclosures available is concerning the straight long enclosures. In this paper, the sound pressure level (SPL) attenuation, early decay time (EDT), and reverberation time (RT30) of the long enclosures with vertical/inclined branches have been studied by the experimental results from the constructed physical scale models, and which also are compared with the straight long enclosure. This experimental investigation gives interesting results on the behavior of sound propagation of the long enclosures with vertical/inclined branches. Compared with the straight long enclosure, the inclined branch makes more difference to the SPL, EDT and RT30 of the long enclosure than the vertical branch though both kinds of branches have the equivalent volume.
中華民國音響學會2006年第十九屆學術研討會論文集=Proceedings of 19th Symposium of Acoustical Society of the Republic of China，12頁