Lettered Aracari is not particularly vocal (Hilty and Brown 1986, Ridgely and Greenfield 2001b, Short and Horne 2001). The primary vocalization of Lettered Aracari is described as "an often long-continued series of guttural cha notes" (Ridgely and Greenfield 2001b); as "a fast series of sharp kkik (or kkuk, or kkek) notes at 2.5 to 3.5 per s, usually in 'strings' of five to 15 notes, punctuated by a double kkek-ek" (Short and Horne 2001); or as a "series of electric grunts: jrnk jrnk jrnk…." (Lane, in Schulenberg et al. 2010).
For a representative audio recording with sonogram, see audio
Lettered Aracari also gives single chak or kak notes (Remsen, in Hilty and Brown 1986, Short and Horne 2001).