Sustainable Construction A Life Cycle Approach in Engineering

predicted, illustrated and listened to. Sound reinforcement is easily integrated in the acoustic
predictions. Odeon uses image-source method combined with ray tracing.” (Odeon Room
Acoustics Software)
Acoustic Simulation of Cases
There are three sources and minimum 11 receiver points in each room. The selected parameters
to evaluate the acoustics of the cases are reverberation time (T30), early decay time (EDT),
distinctness (D50), sound pressure level (SPL) and speech transmission index (STI).
4. EVALUATION OF ROOMS
Each room is evaluated individually. In the plans, score, T30, D50 and STI values of the each
receiver point is marked with a coloured point which simulates the relative magnitude of the
parameter. To mark the values of parameters at the receiver points, percentile (value that
demonstrates a rank based on one hundred percent) of the values are used since by this way, it is
possible to evaluate each receiver point relative to others. Red colour simulates the maximum
values (> 75%) of a parameter within the room while black simulates the minimum values (<
25%). Gray (> 25%) and light red colours (> 50%) simulate the values between maximum and
minimum values (Figure 7.
max
min
Figure 7 Used marks and colours
for evaluation of receiver points
There are four parameters compared for each seat to see the change of the acoustical and visual
conditions from seat to seat. In the following figures, the receiver points are evaluated with the
method that is described above on the plan of each case. First point in the box simulates total
score of the seat (SC). Second one simulates the value of T30. Third point simulates D50 value
of the seat and the last one simulates STI value. D50 and STI values are chosen to make
comparison between sightline score and speech intelligibility. And T30 value is included to see
where the reverberation time decrease or increase. For STI, D50 and SC the higher values mean
better conditions for seats. Most of the time this situation is true also for T30 since almost all
receiver points in the rooms have appropriate values of T30. Also, it may be useful to mention
again that in all rooms, all of the receiver points have acceptable values of STI and D50. For
that reason, comparison of receiver points on the plans shows relative relations between receiver
points, more than defining if they are appropriate or not from the acoustical point of view. From
the point of view sightline scores, it can be said that receiver points that are remarked with black
colour indicates that they have the values below 55, in other words, at that point a spectator can
see less than 50 percent of the stage area without head movement.
SC
T30 D50 STI
Figure 8 An example of used
parameters and marks for evaluation
In the Figures 9-16 plans of the cases are shown. By considering the Figure 9, it is possible to
say that best seat in the F15 is number 7. Although sightline score is not at maximum at that
point, acoustical parameters have the maximum values. Just opposite to the situation in F15,
seat one has high STI value and can be evaluated as one of the best seats in the floor level. In
the balcony level, it is seen that seats in the back row have better values (Figure 10).
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