direct voice

This is a form of ‘physical mediumship’ (so-called because the mediumship results in physical effects, as opposed to being channelled through a medium, which is referred to – whether it is deep trance or light – as mental mediumship) where the physical manifestation is the hearing of a voice independent of the medium.

In other words, the medium could have her/hir/his mouth taped shut, or filled with water, or both, and the sound of the voice would still be heard – and should be similar to that of the voice of the person communicating when they were alive (it won’t be identical owing to lack of vibrations in bones etc).

One explanation I have heard for this is that ectoplasm, a physical substance temporarily (meaning: doesn’t last long enough to do scientific tests on … SIGH) manifested from nonphysical energies, is used to create an artificial voice box; other descriptions state that the sound is projected through an old fashioned ‘speaking trumpet’ (i.e. a non-amplified megaphone).

As with all forms of physical mediumship, this is very controversial. 

You can read more about this here and here.