The most inclusive modern definition of ventriloquial practice is the vocal production of sounds or voices that appear to come from somewhere other than their actual source. However, from antiquity to the present, the cognates of ventriloquism have been associated with such disparate phenomena as demon possession, necromancy, the imitation of multiple and remote voices, belief in a rare natural ability to "throw the voice" or to speak inwardly, and the tendency of humans to mislocate the source of a sound in response to visual and auditory cues.

The two basic types of vocal modulation associated with ventriloquism as a mimetic technique are vocal transformation and acoustic perspective. The former designates a change of voice that is in contrast either to the speaker's normal voice or to other assumed or imitated voices. Acoustic perspective is the principle behind not only the voice-throwing illusion or distant ventriloquism, but also the auditory signification of space and movement in the sign systems of radio drama or cinema sound tracks. The voice-throwing illusion foregrounds the normally unconscious structural operation through which the voice is localized as a speaking agent.

The key to the voice-throwing illusion is vocal imitation of the modulation that sounds undergo traveling between points of distance or through obstacles. These vocal signs sometimes function effectively to misdirect the hearer to a signified source of a sound even without visual cues and purposeful misdirection.