抄録
We have been refering to sundry records and statistically analyzing about acousitc characteristics of auditoriums in Japan. Main results of this paper are following. (1) The average of volume per seat for the peorid of 10 years had been increasing from 1960's to 1980's. The volume per seat of concert halls in 1980's were about 10〜12 (m^3/seat). (2) The reverberation times on 500 .Hz band of empty auditoriums with orchestra shell had been long, but those without orchestra shell had been short from 1960's to 1980's. Therefore, the difference between reverberation time without orchestra shell and with it had become large. (3) The average (for 10 years) of mean absorption coefficients of malti-use-purpose auditoriums had been not so changed on every octave band from 1960's to 1980's, but those of concert hall had fairly become small from 1970's to 1980's.
