The spiritualist religion was founded  in New York by the three Fox
sisters, Katie, Margaret, and Leah in 1848.
These early attempts at spirit communication through seances, mirror-writing
and other techniques would later give way to higher tech approaches at spirit communication.  In the 1920's the brilliant inventor Thomas Edison began
work on a device he believed would make it possible to communicate with the
other side through the use of a machine.
Edison was a man who held no strong personal religious beliefs; however, he
did believe in the spirit world like his parents, who were themselves spiritualists.
His work continued on this device up until his death in 1931.
The facts surrounding this device are anything but complete. After Edison's
death the machine itself, along with any documents, blueprints or schematics
for this device disappeared instead of finding their way into a museum as
would have been expected of any invention of Thomas Edison.
No photograph of this device has ever surfaced to the best of my knowledge.
The stories regarding how it worked state it used a chemical apparatus with
potassium permanganate. Edison's machine was probably influenced by British
scientist Sir William Crooke, inventor of the vacuum tube, with whom he
corresponded regarding this device. Crooke was fascinated with spirit
photography and the paranormal in general.
Edison would mention his continuing work regarding his efforts to build this
device for comunicating with the dead in scientific journals. He was indeed
fortunate to have lived during a time when the scientific community was open
minded and objective. No information can be found regarding the actual
testing of this device; however, there are accounts by actual eye-witnesses who saw
the machine itself.
Work in the field of recording voices of the dead would continue again nearly
20 years later in the 1950's through experimentation with magnetic tape recorders.
This serious work can be considered the beginning of modern EVP (electronic voice phenomenon), the study of recording voices of unknown origin onto tape.