ERATO Proceedings Istanbul 2006.pdf - Odeon

stage building causes the RT to decrease below 0.5 s in almost all the frequency range. The
discrepancies between the two conditions are more limited in the lower frequency range.
T30 [s]
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
Greek
Greek w/o stage
63 125 250 500 1000 2000 4000
Frequency [Hz]
Figure 3. RT comparison between Greek theatres with and without stage building
Then also a modified RO was prepared by removing the aisle and the colonnade in the upper part of
the cavea. This RO setup is also interesting for comparison with other preserved Roman theatres
having similar dimensions but without colonnade. The results in Figure 4 show that there are
noticeable variations only in the lower frequency region where the RT decreases by 30% to 40%.
The medium and higher frequencies seem much less affected.
T30 [s]
2.6
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
Roman
Roman w/o columns
63 125 250 500 1000 2000 4000
Frequency [Hz]
Figure 4. RT comparison between Roman theatres with and without columns on the upper part of the cavea
5.2 Energy Parameters
The parameter Clarity for speech C50 is reported in Figure 5. It can be easily seen that, as for RT,
the values are very similar for RO and HE and are different for GE. Interestingly the Clarity is high
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