E.V.P
E.V.P stands for Electronic Voice Phenomena. This Phenomena occurs when the voices of a Spirit interrupt an Electro Magnetic Field,"E.M.F's", so inturn using audio tape i.e. from a micro cassette recorder reveals these voices where as before they could not be heard by a human ear. It is the same way with a dog-whistle, the dog in this case being the audio recorder. We as humans cannot pick up the sound of this dog-whistle because the frequency is to high. The dog, on the other hand can, because its ear drum is designed for hearing higher frequencies. The audio recorder uses magnets to record onto tape when an Electro Magnetic field is interrupted such as when paranormal activity occurs. This inturn effects the tape i.e."E.V.P"
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 simplifed 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. All that is required to capture voices such as these is 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. Headphones are more or less essential as the voices are 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 to hear voices. White noise, however, is not alleged to be necessary in order to achieve results.
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 specialised audio equipment. For more information on ITC, and extensive instructions, information and examples of EVP, follow the links below.