The song of Lesser Violetear is highly variable between individuals (Barrantes et al. 2008), although songs tend to be more similar among groups of neighboring males than they are to songs of more distant males (Gaunt et al. 1994). The song is described as "a vigorous but unmelodious 2- to 4-note phrase - CHEEP chut-chut, chip CHEEP chut, or CHEET-chup - repeated rapidly for minutes on end" (Stiles and Skutch 1989); and as a loud two-noted tsip-chup or tsup-chip (Hilty and Brown 1986).
The song is ventriloquial, and is given from a high perch, such as a bare twig (Hilty and Brown 1986, Stiles and Skutch 1989). Males often sing near to one another (Gaunt et al. 1994, Barrantes et al. 2008), but do not form true leks (Stiles and Skutch 1989). Songs of males within an aggregate are similar to another, but songs differ between aggregates, suggesting an element of song learning in this species (Gaunt et al. 1994, Barrantes et al. 2008)
Other vocalizations of Lesser Violetear include "a sharp, dry, rather low-pitched chut or zut", or many similar notes, run together into a chatter (Stiles and Skutch 1989).