THE ART AND SCIENCE OF CONCERT HALL ACOUSTICS

VII. EVALUATION OF THE TECHNOLOGY

The technology is definitely not foolproof. It is important for the user to understand that some values in the program are very sensitive to minor changes in job setups. For example, the T30 value of reverberation time is less accurate in more complicated rooms, as evidenced by problems with symmetry when running the Ted Mann Hall. Other values were seemingly accurate, but there is no guarantee they are not also skewed. It is likely that some of the acoustical characteristics calculated by the machine are only accurate in a relative way to the others generated in the simulation.

Furthermore, the auralization technology is not a dependable tool either. It can easily demonstrate the effect of frequency absorption in a hall, but cannot auralize echoes. This is important to the fast evaluation of a hall, and could mislead the researcher. As this is only the second year of auralization being available, it is likely that in the next few years this technology will improve.

The current simulation technology captures many features of a hall, but does not handle two important aspects. Sound diffusion from small-scale features in the hall (i.e. decorations) is not handled. Resonance chambers that radiate sound into the hall the way a piano radiates sound from its “sound board” is also not treated. Including either of these processes will require a significant leap in the technology. I can not see how this leap can be made using the ray-tracing methods in use by all the packages we studied. In absence of information about sound diffusion and resonance chambers, the designer is left with educated guesses concerning some design issues (decorations & resonance chambers) that may separate the good halls from the best halls.