Leo L. Beranek
975 Memorial Dr., Ste. 804, Cambridge, MA 02138-5755
Through the cooperation of many acoustical laboratories, architects, and hall managers, physical measurements of reverberation time (RT), early decay time (EDT), early interaural cross-correlation coefficient [IACC(E)], lateral fraction (LF), sound-pressure level (G), initial-time-delay gap (ITDG), bass ratio (BR), early/reverberant energy ratio [C(80)], and diffusion [IACC(L)] have been collected in whole or in part for 66 concert halls and 10 opera houses. RTs are for both occupied and unoccupied conditions; others are for unoccupied states. The parameters IACC or LF, or both, are available for only 40 of the concert halls. The above acoustical parameters for these halls are individually correlated with the rating categories given in the companion paper [Beranek, ``Determination of Categories of Acoustical Quality in Concert Halls'']. It is shown that six of these quantities seem necessary to correlate physical data with the subjective ratings, namely, RT (or EDT), IACC(E), G, ITDG, BR, and some measure of diffusion not yet developed.