For the afterworld, press 1.
Although suggestions for such an invention come up from time to time among those interested in psychical research, none has ever been built so far as I know. The notion that Thomas A. Edison worked to design a "spirit communication device" is unsubstantiated. Nevertheless, recent advances in electronic voice phenomena and instrumental transcommunication show some promise in using modern recording technology to communicate with spirits on the Other Side.
Symonds's site strikes me as the proverbial curate's egg ("parts of it are very good"). He — if it is a he — throws everything into the hopper in typical New Age fashion: some of it thoughtful and well researched, some that seems to me intuitively valid, and plenty of pitches for dubious products and books. I do not know what, if any, electronics background he has. He describes the proposed afterlife communication device:
If Arthur Ellison were still here, he could probably take a look at Symonds's diagram and in about 30 seconds offer a sound opinion about whether it was likely to work. My guess is not; if something this relatively simple was theoretically valid, Dr. Ellison or someone like him would have built one.
An electric field emanating from a charged capacitor attached to a very, very sensitive microphone inside a glass vacuum chamber or bell jar would have to be used in this case. … The vacuum is necessary to reduce influences from air vibrations and to allow dramatically increased sensitivity to the finer and highly rarified electrical field particles (electrons), vibrations or variations which are hopefully much more likely to be influenced by spiritual entities and/or energies. My greatest hope is that I would be able to capture a clear, natural sounding voice using this method.
For now, mediumship seems to be the best source of information from those who have passed through the transition called death. Probably the best group of recorded mediumistic communications are those transmitted through Leslie Flint. I have listened to only a fraction of the tapes (they are long, my time available is short) and am certainly not about to offer a categorical opinion about their veracity or whether the voices are those of the putative deceased persons. But most of what I've heard is impressive in one way or another.
Mediumship, especially direct voice mediumship (where the voice is said to be that of the discarnate communicator, not the medium's own), has definite problems. Most "messages" are trivial, rambling, or spiritualist boilerplate. Where they can be compared with recordings or memories of the living communicator, the direct voices and languages often do not match.
Does that mean mediumistic communication is invalid? No — it means it's difficult. The spirits are in a different realm from ours, on a different vibrational level. They don't have physical vocal cords. Richard Hodgson, an early investigator for the Society for Psychical Research, concluded based on his experimental work with mediums:
If, indeed, each one of us is a spirit that survives the death of the fleshly organism, there are certain suppositions that I think we may not unreasonably make concerning the ability of the discarnate spirit to communicate with those yet incarnate. Even under the best conditions for communication which I am supposing for the nonce to be possible, it may well be that the aptitude for communicating clearly may be as rare as the gifts that make a great artist, or a great mathematician, or a great philosopher.This makes sense, and many mediums and psychical researchers have said something similar. Communication with those on the other side is difficult for us, but probably nowhere near as difficult as it is for them.
Again, it may well be that, owing to the change connected with death itself, the spirit may at first be much confused, and such confusion may last for a long time; and even after the spirit has become accustomed to its new environment, it is not an unreasonable supposition that if it came into some such relation to another living human organism as it once maintained with its own former organism it would find itself confused by that relation.
The state might be like that of awaking from a prolonged period of unconsciousness into strange surroundings. If my own ordinary body could be preserved in its present state, and I could absent myself from it for some days or months or years, and continue my existence under another set of conditions altogether, and if I could then return to my own body, it might well be that I should be very confused and incoherent at first in my manifestation by means of a human body. I might be troubled with various forms of aphasia [inability to speak] and agraphia [inability to write], might be particularly liable to failures of inhibition, might find the conditions oppressive and exhausting, and my state of mind would probably be of an automatic and dream-like character.