Abstract: The acoustical quality of an ordinary hall, namely the reverberation time and the spatial non-uniformity of sound pressure level in audience area, was simulated on a microcomputer. Comparison between calculation, measurement and simulation of reverberation time shows that the reverberation time from simulation is closer to that from measurement, if the absorption of the audience is properly chosen, in the frequency range from 125 to 4000 Hz, the average deviation is less than 10%. For the spatial non-uniformity of sound pressure level, there is a good correspondency between the simulation and the measurement. In addition, some details in simulation were discussed.