The song of Flame-throated Warblers has been described as "a weak dry buzz, zeeeeeoo" (Ridgely and Gwynne 1989) or as "a weak, dry, insectlike buzz with rising inflection, preceded by several short notes or a little trill: pee pipipipi shwaaa?" (Stiles and Skutch 1989). An alternate song type, heard only near dusk, is a short twitter (A. Spencer, xeno-canto).
The call is a "sharp, high-pitched chit or chip" (Stiles and Skutch 1989).
No information is available on geographic variation, phenology, the extent of their repertoire, or the social context of their songs.