Electronic Voice Phenomena

Electronic Voice Phenomena (or EVP) is where human-sounding voices from an unknown source are recorded onto electronic media, usually audiotapes. At the time of the recording no voice is actually heard, but only during playback is something heard. Sometimes noise filtering and amplification is required to hear the voices.

EVP quality varies. Some EVP is clearer than others, some are difficult to determine and are open to interpretation as to what they are saying. They vary in gender, age, tone and emotion. EVPs are usually single-word phrases or short sentences, but sometimes play back as grunts, groans, growling and other vocal sounds, and in various languages. Sometimes EVPs are mechanical-sounding; sometimes they sound naturally spoken.

Researchers categorize EVPs into three distinctive classes:

• Class A: Very clear, easily understood, with distinct formations of words. Class A EVPs are also usually the loudest.
• Class B: Unclear or indistinct, with word formations often difficult to understand, and certain syllables are distorted or very unclear. This class is the commonest type of EVP and tend to be softer than Class A EVPs.
• Class C: Distorted, indistinct and barely audible (often as whispers), and very difficult to understand word formations.

Many EVPs are simply recordings of anomalous voices, but sometimes the voices seem to respond directly to questions asked by the researcher. And, once again, the response is not heard until afterwards, when the audiotape is played back.


There are many theories on what EVPs actually are, but no one knows for certain, so it remains something of a mystery. Some of those theories are:

• They are the voices of spirits, i.e. people who have died but still remain earthbound. Many researchers visit cemeteries for EVP recordings (often with great success). In this context, it is usually referred to as ITC (or Instrumental Transcommunication).
• They are researchers' own thoughts recorded onto the magnetic tape, in the same way it is thought that the energies from "residual hauntings" are recorded in certain areas.
• They are ordinary background noises, random sounds or voices picked up from radio, cell phones and other electronic sources. The brain will naturally search for patterns it can recognize, especially visual and auditory, reforming them into something it can identify with.

Other theories are:

• They are beings from another dimension, one of the many planes of existence, or alternative universes. They are able to utilize this method to communicate.
• They are the voices of angels or demons, but this theory is primarily influenced by religious conviction.
• They are hoaxed, created by audio rendering software and recorded onto audiotape.

Nowadays, with modern sound analyzing software, it is possible to isolate "white noise", background sounds, and "normal" voices to distinguish anomalous sounds and voices. It is also possible to identify each sound wave individually.