Further investigation on concert hall acoustics

Abstract

Since the book [Y. Ando, Concert Hall Acoustics (Springer, New York, 1985)] was published, further work has been carried out. The results demonstrate that the running autocorrelation function of source signals may better describe preferred conditions of sound fields than does the long‐time autocorrelation function. The minimum value of the effective duration of the running autocorrelation function of music signals for the interval used for the subjective preference judgment corresponds well to the preferred initial time delay gap between the direct sound and the first reflection when the amplitude A1 = 0 dB. This was discovered when Japanese music containing a so‐called “MA,” a stationary sound passage without any rapid movement, was used as a source signal. Also, it was found that a flat frequency characteristic of the subsequent reverberation time is the optimal condition, and that it may be calculated by the minimum effective duration of the running autocorrelation function of the source signal. Several other results will be presented.