Reexamination of the favorable reverberation time of concert halls measured in a 3D synthesized sound field

Abstract

This paper examined the favorable reverberation time in concert halls for orchestral music. Anechoic music sources created by session recording were reproduced by a virtual orchestra with 45 loudspeakers set on concert hall stages and were recorded with a 32-channel spherical microphone at audience seats. Four orchestral music excerpts from the classical, romantic, and contemporary periods were chosen. By a fourth order Ambisonics playback in the laboratory, a series of psychological experiments were conducted. Twenty-one music experts judged the reverberance and clarity of the presented sound. It is found that mid-frequency reverberation time RT_M (octave band average for 500 and 1,000 Hz) and early decay time EDT_M are both highly correlated with the reverberance, and their favorable values are determined by the tempo: speed or pace of the music, not by the chronological classification of music. For the tempo from Presto to Allegro, the favorable RT_M ranges from 1.7 to 2.2 s, and if extrapolation of this result is assumed, the favorable RT_M ranges from 2.0 to 2.2 s from Presto to Andante.