Figure 2.

Oscillograms (Upper) and sonagrams (Lower) of composite communication calls (nos. 2–11) of the mustached bat P. parnellii. Composites are made up of two (all except no. 6) or three (no. 6) distinct components (syllables) that the bats combine without an intervening silent interval (connecting points of syllables indicated by arrows). The composites (e.g., bUFM-TCFs, no. 2) are named according to the simple syllables (e.g., bent Upward FM-short True Constant Frequency) from which they are composed (for complete nomenclature, see ref. 8). For determining a unit’s spontaneous activity a no-stimulus interval (i.e., no. 1, not shown) was used at the beginning of each composite series.