The influence of late arriving energy on spatial impression

New subjective experiments using sound fields simulated in an anechoic room confirm that spatial impression in concert halls is composed of at least two distinct aspects: apparent source width and listener envelopment. Previously published research has shown that apparent source width is related to the relative level of early lateral reflections. This new work demonstrates that listener envelopment is related to the level, direction of arrival, and temporal distribution of late arriving reflections. It is further shown that increased amounts of listener envelopment decrease the subject’s sensitivity to changes in the apparent source width of the sound field. Listener envelopment is related to objective acoustical measures, and the implications for concert hall design are discussed.