**4.** *What* **is evaluated?**

To ensure uniform measurements, some were repeated in the four environments, while others were recorded in specific places, considering the normal musical use of the environments. Tracks 1–13 were repeated in the four environments. However, tracks 17 (the final part of Stravinsky's *Firebird Suite*) and 18 (a solo harp piece by Lucien) were reproduced

**Figure 3.** The plans of the four environments: Plaça de Sant Felip Neri, Carrer de Santa Llúcia, Plaça de Sant Iu, Plaça

**Figure 2.** Recordings in Plaça de Sant Felip Neri, Barcelona.

48 From Natural to Artificial Intelligence - Algorithms and Applications

**Figure 1.** Recordings in the anechoic chamber of Universitat Politècnica de València, Gandia.

del Rei.

The four environments were studied using a reproduction-recording system. In this system, an impulse signal previously calibrated in the Anechoic Chamber was emitted in the environment. This signal was captured in different positions in each environment, as already mentioned. **Figure 3** shows the measured positions. Each of the recording points was subdivided into two channels corresponding to left (L) and right (R). Therefore, the naming of each recording consists of the number of the recording point, followed by an underscore and capital letter L or R: 1\_L, 1\_R, 2\_L, 2\_R, etc.
