Directional characteristics of late sounds in concert auditoria

Objective measurements are performed in auditoria to clarify the directional characteristics of late sounds, which correlate with listener envelopment. The measured values with directional microphones reveal the ranges of the level variation of lateral, longitudinal and vertical energy in real sound fields. It is also found that the level attenuation coefficient of vertical component is highest. Furthermore, directional late energy ratios are considered in order to account for the spatial balance of late sounds arriving at a receiver. The results show that the directional distribution of late sound is an important factor in evaluating the sound fields of auditoria.