The voice of Southern Emerald-Toucanet is described variously as "a rapid ser[ies] of short took or churt notes, about 2-3 per sec." (Colombia; Hilty and Brown 1986); as "a guttural, grinding grá-val, grá-val, grá-val .... varied to roouk, roouk, roouk,... (sexual difference?) at almost 2/sec." (Venezuela; Hilty 2003); as "a persistent and fast rek-rek-rek-rek or rr-rek, rr-rek, rr-rek, often with a barking quality" (Ecuador; Ridgely and Greenfield 2001b); and as "a long series of grinding grunts grra grra grra... or barking yaps yak yak yak yak yak" (Lane, in Schulenberg et al. 2010).
Additional recordings of vocalizations of Southern Emerald-Toucanet can be heard at Macaulay Library and at xeno-canto (Santa Marta group; Gray-throated group; Andean group; and the Black-throated group).