Electronic Voice Phenomena, or EVP, refers to the claimed occurrence of "spirit voices" that are said to manifest themselves on audio recordings.

Such "voices" are said to be known for being rapid, faint, and often spoken in grammatically unusual and simplified language—or even multiple languages during the same sentence. The interpretation of such recordings is often highly subjective, and may differ from listener to listener; some listeners may hear nothing at all, while others report hearing specific phrases or sentences.

The alleged phenomenon was first noted by Friedrich Jurgenson who, after playing back a recording of birdsong in the Swedish countryside, is said to have noticed the presence of a faint Norwegian voice talking about 'birds at night'. Jurgenson assumed this must have been a stray radio broadcast, only there was no radio receiver at the remote location where the recording had been made. Whatever the cause, it prompted Jurgenson to make further recordings in his home.

Voices that were not present during the recording allegedly continued to appear on playback. They were said to refer to him (and his dog) by their names and nicknames, predict an incoming telephone call (and name the caller, Jurgenson's wife), and respond to questions and comment on the people and conversation physically present and accountable for in the room.

Since Jurgenson's report, thousands of people all over the world have attempted to replicate the spirit voices phenomenon, claiming success in many cases. They use no special equipment to capture voices such as these, only a microphone and a means of recording, such as a tape/minidisc/CD recorder or a computer, and patience: It is said it can take months of diligent recording before voices appear. Proponents recommend the use of headphones, because the voices are often faint, and a computer for processing the recordings is very helpful.

The quality, volume and durations of recordings are said to be increased by using a sound source placed within audible distance of the microphone during recording. Typically this would be a radio tuned to between stations so only white noise is audible; the theory being that this provides an acoustic basis for the voices to be constructed from, similar to vocoder technology. An alternative explanation is that the white noise provides random sounds that may be interpreted as voices by people who expect or want to hear voices. This explanation is consistent with the theory that the entire "phenomenon" is an example of pareidolia, in which a vague or random stimulus is mistakenly perceived as recognizable.

There is a more complex form of EVP known as ITC: Instrumental Transcommunication, which is the forming of extended, two-way contacts with the "spirit world" through means such as telephones, televisions, computers, and specialized audio equipment.

In the 1920s, Thomas Edison postulated that if spirits or ghosts where to be contacted, it would be through more sensitive machines than the current methods such as Ouija boards. An experiment conducted by a group called The Scole Experiment, a machine called a Germanium Receptor was used. The explanation for the use of the Germanium Receptor was that during a séance, unopened films were present and the spirit said that the key to communicating with them was on the film. On the film later found was a set of instructions allegedly signed with Edison’s signature. The machine has been said by its proponents to be quite successful in recording messages from the other side.

EVP in fiction

• Pattern Recognition by William Gibson - The main character's mother tries to convince her that the father is communicating with her from recordings after his death/disappearance in the September 11, 2001 attacks.

• Ubik by Philip K. Dick - A character (Glenn Runciter) communicates after his death(?) via vidphone.

• White Noise - A movie starring Michael Keaton in which his dead wife tries to contact him via EVP.

External links

• World ITC.org - featuring online versions of researchers' books and EVP/ITC examples and instructions
• American Association of Electronic Voice Phenomena
• The EVP Recordings - blog about EVP
• Ghostweb.com EVP Page
• Ghostwave.com EVP Page
• Skeptic's Dictionary entry on EVP