Figure 3. Design of the playback experiment.

S is the subject, with its left and right neighbours established respectively in the territories at the left side (NL) and the right side (NR). The composition of each stimulus broadcasted by the loudspeaker placed at either boundary is indicated in the box. Phases of songs broadcasted from the correct side (belonging to the correct neighbour) are in bold. Dotted lines indicate the territorial borders of subjects S, NL and NR. S1 indicate stimuli in which song produced during the ascending phase was broadcasted from the correct and song produced during the level phase from the incorrect side, S2 indicate stimuli in which song produced during the level phase was broadcasted from the correct and song produced during the ascending phase from the incorrect side.