1. 3) I. Nakayama, “Preferred delay conditions of early reflections for performers,” Proc. 12th ICA, Vancouver Symposium, pp. 27–32 (1986).
2. 4) S. Nakamura and S. Shirasuna, “Study of the conditions of sound reflection preferred by solo singers on the concert stage,” Proc. 12th ICA, E6-3 (1986).
3. 6-channel recording/reproduction system for 3-dimensional auralization of sound fields.