## 3 Results  
### Objective Results  
Figures 5-9 show the results of each objective room acoustic parameter in all the considered hall conditions. Each parameter is given with respect to the source-to-receiver distance (S1 and S2). Moreover, the figures provide the objective acoustic parameter differences between the configurations Df-Dm, Df-Dr, Dm-Dr for an easier direct comparison to the JND values for the absorptive (-A) and reflective (-R) conditions, respectively. Differences within \(\pm\)1 JND of the parameters are highlighted through a gray area. A summary of these differences has been given numerically in the tables in Appendix A. The results of _EDT_ (Figure 5) do not show a strong dependence on the source-to-receiver distance for both S1 and S2 in both the reflective (-R) and absorptive (-A) conditions. _EDT_ values of the reflective conditions result higher for source location S2 compared to S1 for source-to-receiver distances between 8-12 m. The \(\Delta\)_EDT_ graph shows that there are a few significant differences between the configurations Df-Dm, Df-Dr, Dm-Dr in the reflective (-R) and absorptive (-A) conditions, i.e., >1 JND. These differences result higher for source location S2 and occur at a larger number of receivers in the absorptive (-A) conditions. However, no significant trend could be observed with respect to the source-to-receiver distance. The results of \(T_{30}\) (Figure 6) show a decrease at the farthest positions for both S1 and S2 in the reflective conditions Df-R, Dm-R, Dr-R, and All-R. Conversely, there is no decreasing trend in the absorptive conditions Df-A, Dm-A, Dr-A, and All-A. \(T_{30}\) values of the reflective conditions result higher for source location S2 compared to S1 for the nearest receivers. Very few receiver locations seem to present differences (\(\Delta\)\(T_{30}\)) higher than the JND between the different diff  
Figure 5: _EDT_ parameter averaged over 500 Hz and 1000 Hz for S1 and S2 source-to-receiver distance. \(\Delta\)_EDT_ represents the parameter differences between the configurations Df-Dm, Df-Dr, Dm-Dr in the reflective (-R) and absorptive (-A) conditions. Differences equal \(\pm\)1 JND of the parameters are highlighted through a gray area. Df-Dr, Dm-Dr in the reflective (-R) and absorptive (-A) conditions. However, no significant trend can be detected considering the overall receivers and the source-to-receiver distance. The results of \(C_{80}\) (Figure 7) present different trends for S1 and S2 with respect to the source-to-receiver distance in both the reflective (-R) and absorptive (-A) conditions. Generally, it can be noticed that \(\Delta C_{80}\) values present a few differences higher than the JND between the different diffuser locations Df-Dm, Df-Dr, Dm-Dr in the reflective (-R) and absorptive (-A) conditions. However, it not possible to detect a significant general trend of differences due to the diffuser location when a comparison is made overall the source-to-receiver distances. The results of \(D_{50}\) (Figure 8) show a decrease at the farthest positions both for S1 and S2 in the reflective (-R) and absorptive (-A) conditions. It can be noticed that \(D_{50}\) values present a higher variability in the absorptive conditions at each receiver position for both sources. Generally, it can be noticed that \(\Delta D_{50}\) values present a few differences higher than the JND between the different diffuser locations Df-Dm, Df-Dr, Dm-Dr in the reflective (-R) and absorptive (-A) conditions. However, no significant trend can be detected considering the overall receivers. The results of \(T_{\rm s}\) (Figure 9) show an increase at the most distant positions both for S1 and S2 in the reflective (-R) and absorptive (-A) conditions. Only a very few receiver locations seem to present differences higher than the JND between the different diffuser locations. This is observed mainly for the reflective (-R) conditions. Figure 6: \(T_{30}\) parameter averaged over 500 Hz and 1000 Hz for S1 and S2 source-to-receiver distance.