## 3 Results  
### Objective Acoustic Parameters Results  
The results have been presented in Figure 7; the plots show the results of each objective room acoustic parameter in octave band frequency as an overall mean value over the receiver positions. It can be noticed that _EDT_ shows a better matching between the simulated and the measured data (<JND). Conversely, \(T_{30}\) evaluated for the diffusive condition (gray curves) showed differences higher than the JND at 2000 and 4000 Hz. Also \(C_{80}\) and \(D_{50}\) showed differences higher than the JND at some frequencies for both diffusive and reflective conditions. Overall, the simulated results show that the acoustic parameter values are sensitive to the presence of the diffusive or reflective surfaces as in the in-field measured results. The differences higher than one JND have been considered significant (Figure 7). It can be noticed that these differences are more evident at mid frequencies. In Table 3 are shown the differences of the parameter values between the reflective and diffusive conditions and compared to the JND of each parameter. _EDT_ increased from the reflective to the diffusive configuration by more than one JND (JND\({}_{EDT}\) = 5% of the lowest value of _EDT_, which in this case is about 0.05 s). Also, \(T_{30}\) increased from the reflective to the diffusive configuration by more than two JNDs (JND\({}_{EDT}\) = 5% of the lowest value of \(T_{30}\), which in this case was about 0.05 s). Conversely, \(C_{80}\) decreased by about one JND (JND\({}_{C80}\) = 1 dB) in position 2 when comparing DM and RF simulations, but no significant difference was obtained in the comparison between DF and RF simulations. \(D_{50}\) decreased by more than one JND (JND\({}_{D50}\) = 0.05) when varying from the reflective (RF) to the diffusive (DM) configuration in positions 3 and 5. While, no significant variations could be found when varying from RF to DF configuration. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c} \hline  & \multicolumn{2}{c}{**Distance [m]**} & _EDT_ [s]** & \(T_{30}\) [s] & \(C_{80}\) [dB] & \(D_{80}\) [-1] & _IACC\({}_{\text{entry}}\)_ [-1] & _IACC\({}_{\text{Late}}\)_ [-1] \\ \hline R & **d-S** & **d-W** & **DM-RF** & **DF-RF** & **DM-RF** & **DF-RF** & **DM-RF** & **DF-RF** & **DM-RF** & **DF-RF** & **DM-RF** & **DF-RF** & **DM-RF** & **DF-RF** \\ \hline
1 & 6.28 & 2.15 & **0.10** & **0.09** & **0.17** & **0.16** & \(-\)0.76 & \(-\)0.61 & \(-\)0.02 & 0.00 & 0.045 & **0.109** & 0.065 & \(-\)0.007 \\
3 & 6.02 & 4.92 & **0.16** & **0.08** & **0.17** & **0.20** & **\(-\)1.71** & 0.50 & \(-\)**0.09** & 0.02 & 0.017 & **0.097** & \(-\)0.038 & \(-\)0.015 \\
5 & 6.96 & 7.69 & **0.12** & **0.11** & **0.15** & **0.17** & \(-\)0.45 & 0.17 & \(-\)**0.06** & \(-\)0.03 & \(-\)**0.091** & \(-\)0.011 & 0.063 & 0.011 \\  & JND & 0.05 & & & & & & & & & & & & & \\ \hline \end{tabular}
\end{table} 
Table 3: Differences of the objective acoustic parameters between the DM and RF simulations and DF and RF simulations in position 1, 2, and 3. Differences higher than one JND have been highlighted in bold. The differences are between mean values at 500–1000 Hz (_EDT_, \(T_{30}\), \(C_{80}\), \(D_{50}\)) and 500–2000 Hz (_IACC\({}_{\text{early}}\)_ and _IACC\({}_{\text{late}}\)_). The results of _IACC_ values in receiver positions 1, 3, and 5 have been presented in Figure 8 as a function of the distance from the lateral variable wall. The analyses aimed to highlight the differences in the _IACC_early and _IACC_late values in both configurations of the simulated hall with respect to the measured results. It is shown that differences higher than one JND (JND\({}_{IACC}\) = 0.075) in _IACC_early occur in receiver positions 1 and 3 between the measured and the simulated results for the reflective condition. The differences between the simulated and measured results for the diffusive condition, are higher for the DF model at the receiver position 1, which was close to the lateral wall.