Presence which theoretically should not be present is a very intense form of liveness.
The spectre of death (conjured into the now) is very 'live'.
Making a deliberate decision to present only the voice may assist the ‘making present’ of those who cannot be physically present (for example, those who can’t show their face).
The term ‘acousmatic sound’ means an invisible sound source, and can be relevant to voice. The term comes from ‘the Acousmatics’, pupils of the philosopher Pythagoras who listened to him deliver his lectures from behind a curtain (it was thought that visual distraction would impinge on the purity of his teachings.) In acousmatic art, one hears sound from behind a "veil" of loudspeakers, the source invisible.
#illusionofpresence