## 4 Results and Discussion
### Facade with Two Walls
The values of the unweighted global attenuations \(\Delta D_{\text{FL}}\) for an isolated building and for a building with a reflecting surface placed at 10 m from the corner room are shown in Table 2.  
To obtain the attenuations \(\Delta D_{\text{FL}}\) relative to a certain configuration from Table 2, it is necessary to select the column corresponding to the dimension of the room. Such dimensions are expressed by a double pair of numbers. The first number indicates the dimension of the room in the plan, opposite to the loudspeaker position. The second number indicates the dimension of the room in the direction of the loudspeaker. For example, for an isolated building, the attenuation \(\Delta D_{\text{FL}}\) for a ground floor room having dimensions 6 m \(\times\) 5 m is 22.4 dB when the loudspeaker is placed in position B and 1.9 dB when the loudspeaker is placed in position F. The attenuation values related to the intermediate dimensions of the room can be obtained by linear interpolation. It can be observed that the maximum variation of the attenuation as a function of the width of the room is 2.0 dB. The contribution of a building located 10 m away can lead to a decrease in the attenuation of up to 7 dB in the case of a 6 m \(\times\) 6 m room at the ground floor when it is opposite the edge of the building (position of the loudspeaker \"1b\" in Figure 5). The minimum attenuations for positions A-B-C-D for floors F0, F1, F2 and F3 are 20.4 dB, 18.0 dB, 13.2 dB and 12.7 dB, respectively. In the case of a building placed 10 m from the facade, the minimum attenuations become 15.7 dB, 12.4 dB, 12.5 dB and 11.5 dB, respectively. The biggest differences can be observed for the ground and the first floors. For positions \"2a\" and \"2b\" of Figure 5 it was verified, through simulations, that the attenuation is comparable to that of the case without a reflecting building at 10 m. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & **A (1b)** & **B (1b)** & **C (1b)** & **D (1b)** & **E (1a)** & **F (1a)** & **G (1a)** & **H (1a)** \\ \cline{2-10}  & **3 \(\times\) 6–6 x 6** & **3 \(\times\) 5-6 x 5** & **3 \(\times\) 4–6 x 4** & **3 \(\times\) 3-6 x 3** & **3 \(\times\) 6–6 x 6** & **3 \(\times\) 5-6 x 5** & **3 \(\times\) 4–6 x 4** & **3 \(\times\) 3-6 x 3** \\ \hline \multirow{2}{*}{F0} & 21.1–22.7 & _20.8–22.4_ & _20.5–22.1_ & _20.4–22.0_ & _1.1–2.5_ & _0.4–1.9_ & _1.6–2.3_ & _1.2–2.0_ \\ \cline{2-10}  & **16.9–15.7** & **18.7–16.9** & **18.5–16.5** & **18.3–16.7** & **1.0–2.3** & **0.5–1.8** & **1.3–2.1** & **0.7–1.6** \\ \hline \multirow{2}{*}{F1} & 19.8–21.4 & _19.3–20.8_ & _18.7–20.3_ & _18.0–19.5_ & _11.5–12.8_ & _4.2–6.1_ & _3.1–3.8_ & _2.3–3.2_ \\ \cline{2-10}  & **14.4–13.5** & **14.0–13.1** & **13.5–12.9** & **12.8–12.4** & **10.9–10.8** & **4.1–5.5** & **3.0–3.5** & **2.2–3.0** \\ \hline \multirow{2}{*}{F2} & 14.8–16.0 & _14.4–15.6_ & _13.8–15.1_ & _13.2–14.4_ & - & - & - & - \\ \cline{2-10}  & **13.3–13.4** & **13.3–13.9** & **12.6–13.2** & **12.5–13.2** & - & - & - & - \\ \hline \multirow{2}{*}{F3} & 14.3–14.7 & _13.2–14.2_ & _13.2–14.4_ & _12.7–13.8_ & - & - & - & - \\ \cline{2-10}  & **12.6–13.3** & **12.0–12.7** & **11.9–12.6** & **11.5–12.1** & - & - & - & - \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Unweighted global attenuation range \(\Delta D_{\text{FL}}\) [dB] with isolated building (italic font) and with a reflecting surface at 10 m from a near building (bold font). Figure 5: Configuration of the sources in case of a building placed at 10 m from the building featuring the corner room. Example of the ground floor.