## 3 Results
### Listening Tests Results  
Initially a one-way analysis of variance (ANOVA) has been performed in order to determine whether the different types of motifs affect the perception of the differences between the reflective condition and the two diffusive conditions. It showed that the results obtained for the different motifs have no significant influence (F(1,30) = 1.25, \(p\) > 0.05) on the subjective results. Thus, the subject answers have been analyzed considering the overall results independently of the motif. Figure 9 shows the results of the listening tests. The perception of the differences between the two acoustic wall conditions resulted to be more difficult when the signals were played in the DF condition compared to the RF (Figure 9a). The overall correct answer rate in this case is below 50%. Thus, it was not possible to define a threshold. Significant results were obtained when comparing signals between the DM (diffusive modeled) and RF (reflective flat) conditions, which reached an overall correct answer rate above 50% at the different listening positions. Therefore, for this comparison it was possible to build the psychometric function, which was fitted to the experimental data as shown in Figure 9b. The psychometric curve obtained in the previous study [5] with measured impulse responses has been reported in gray. The graph depicts on the \(y\)-axis the probability of a correct answer, i.e., the performance level as a function of the stimulus, and on the \(x\)-axis the stimulus intensity associated with the distance from the variable wall. The black circles represent the data collected through the listening tests, i.e., the proportion of correct answers for a given stimulus. The solid line shows the best-fitting psychometric function assigned to the collected experimental data. The horizontal bars depict the confidence intervals, which show the variability of the psychometric function evaluated at 20% (0.20), 50% (0.50) and 80% (0.80) of the interval above the chance threshold (\(\gamma\)), which is equal to 33% (0.33). Since the detection tests presented in this work have been designed according to the forced choice criterion, the threshold must be set to one half of the interval between the guessing (\(\gamma\)) and the lapsing rate (1\(-\lambda\)). The threshold is indicated with the dashed vertical line and is the estimated value results of about 7.50 m, which corresponds to listening position at receiver 5. On the other hand, the threshold obtained with the in-field measured impulse responses was estimated at about 2.15 m, which corresponds to the receiver position 1. The value for the cumulative probability estimate (CPE) has been reported in Figure 9b. According to [PERSON] and [PERSON] [58; 59] a CPE greater than 0.95 denotes that the fit is inappropriate. In this case, the CPE is equal to 0.79 and 0.21 for the simulated and measured signal-based tests, respectively, and thus the psychometric curve correctly fits the data.  
During the test, each listener could comment on the differences that guided his/her choice for each single triad. The results of these comments are depicted in Figure 10 as the percentage of listeners that reported the attributes given in the \(x\)-axis. More than 50% of the subjects could detect differences in reverberation and coloration. Subjects could detect also sound level, spaciousness and source location effects. As in the listening test with measured impulse responses, they declared that they perceived a larger or smaller volume, and closer or a more distant sound source.