Introduction to Acoustics

Concert Hall Acoustics Based on Subjective Preference Theory 10.4 Acoustical Measurements of the Sound Fields in Rooms 381
4
1
2
3
0
5 10 (m)
Fig. 10.49 Left panel plan; right and bottom panel cross sections of the Uhara Hall, Kobe. Four source positions, 1, 2, 3and4on
the stage, which were switched in the paired-comparison test of subjective preference without moving subjects from seat to seat.
There were 21 listening positions including neighboring seats
10.4.2 Subjective Preference Test
in an Existing Hall
The subjective preference judgments for different source
locations on the stage at Uhara Hall, Kobe, were performed
by a paired-comparison test at each set of seats.
The relationship between the resulting scale value of
subjective preference and the physical factors obtained
by calculation, using architectural plan drawings, was
examined by factor analysis [10.84]. Calculated scale
values of subjective preference were reconfirmed for the
Uhara Hall (Fig. 10.49). The physical factors at each
set of seats for four source locations on the stage were
calculated. In the simulation, the directional character-
istics of the four loudspeakers used in preference tests
were not taken into consideration for the sake of convenience.
The simulation calculation was performed up to
the third order of reflection. Due to a floor structure with
a fair amount of acoustic transparency, the floor reflection
was not taken into account for the calculation, and
part of the diffuser ceiling was regarded as a nonreflective
plane for the sake of convenience. In the calculation
of the IACC, the listeners faced toward the center of the
stage, so that the IACC was not always a maximum at
the interaural time delay τ = 0.
The hall contains 650 seats with a volume of
4870 m 3 . Four identical loudspeakers with the same
characteristics were placed 0.8 m above the stage floor,
Part C 10.4