Like other vultures, King Vulture does not have a voice box; therefore, it makes no calls or songs. However, in courtship, they have been reported to emit guttural grunts and whistling hisses (Ferguson-Lees and Christie 2001). Smith (1970) described low croaking noises emitted by adults when nest was threatened. Nestlings give soft painful cries and croaking sounds when threatened (Schlee 1995, Mendes de Carvalho Filho et al. 2004).
West (1988) discusses six different types of vocalizations: 1) a raspy growling sound elicited when other species flew near the nest, 2) groan followed by a raspy growling sound uttered by the nestling when the adult changed its perch in the nest tree, 3) hoarse vocalization in response to viewing humans, 4) a pig-like squeal made by adult as it moved about in the nest cavity, 5) short raspy saw cutting sound produced by nestling after the adult left the cavity, and 6) a scream type of vocalization uttered when the nestling viewed two Turkey Vultures land on a branch near the nest.