In auditoriums, the acoustical quality differs from one seat to another. This paper examines the spread of acoustical quality in concert halls having three different shapes, shoebox, non-shoebox, and surround. The total acoustical quality is defined as: TAQ = [IACC_(E3)-IACC_(E3,Avg)]~(3/2)+ [G-G_(Avg)]~(3/2)+ [EDT-EDT_(Avg)]~(3/2). If we write IACC_(E3) = log(iacc_(E3)) and G = 10log(E), we can write the relative spread as: ATAQ= V([Aiacc_(E3)/iacc_(E3,Avg)]~2 + [AE/E_(Avg)]~2 + [AEDT/EDT_(Avg)]~2). The comparison of the spread in ATAQ was measured in 18 concert halls. The results were that the spreads depend significantly on the hall shape, and the largest spread is in the parameter IACC_(E3). Thus, IACC_(E3) is judged to be the most significant quantity in the measurement of the spread in acoustical quality from one shape of hall to another.
展开▼
