The song of the Rufous-tailed Jacamar has been described as a loud, high series of notes ending in a trill, gaining in pitch and speed through the song: "peeo, peeo, peea, pee-pee-pee-pe-pe-pe-pe-pe-e-e-e'e'e'e," with a concluding trill (Hilty and Brown 1986). Skutch (1962) observed that there may be geographic variation in the songs; individuals in northern Central America accelerated through the song and then reached a climax after which notes became farther apart again. The call note may be a squeak or a whistle (Skutch 1962); other descriptions of the call are "a sharp, inflected peeup" (Slud 1964) or "a sharp, nasal peeap" (Hilty 2003).
Nestling Rufous-tailed Jacamars are quite vocal. By the time the young are six days old, eyes still closed, the birds are making tiny calls. At two weeks, eyes open and long pin feathers present, the call develops into a series of whistles that starts low and increases in pitch, volume, and rapidity until a near-trill is reached. The nestlings are vocal much of the day, from the first light of dawn and into the evening beyond the vocalization time of other diurnal birds. At three weeks, the end trill has become more developed, like that of the adult. Instead of calling all day, continuously, the young sang in response to their parents and to their hunger (Skutch 1962).