In this study, the ray tracing computer program has been developed and subsequently, the echogram is obtained. From this echogram, we find the sound decay curves at the various positions of receiver. The speech intelligibility parameters ($C_80$ and Speech Transmission Index) are also calculated. Comparison of the computer simulation with the results of experiment is very favourable.
We can also extend this program to the multi-sound source system. And this ray tracing program can be used to predict the various acoustical characteristics of room and to design architectures such as rooms, theaters and concert halls.