EVP Class A, B & C; EVP-R; EVP-X
As you are probably aware, EVP stands for Electronic Voice Phenomenon which is one of the benchmarks of paranormal investigations.
EVP’s are a subset of Instrumental Transcommunication which is defined as the use of technological equipment to record a visual image or the voice of a deceased person. EVP, in particular, makes use of audio recording devices in hopes of capturing a spirit voice that was not audible at the time of the recording, but is heard upon playback. Digital handheld recorders are primarily used today; but previous EVP research was conducted using audio cassette, reel-to-reel, or even answering machines to record these disincarnate voices.
EVP was first discovered in 1901 when Waldemar Bogoras was recording a Siberian shaman with his Edison Phonograph. There were several people who researched the intricacies of Electronic Voice Phenomenon, but this research remained in rather obscure books and papers. This all changed when EVP was propelled into the public consciousness fully in 1971 with the American publication of Konstantin Raudive’s “Breakthrough: An Amazing Experiment in Electronic Communication with the Dead.” This seminal work on EVP was the result of years of research and tangible recorded results.
In Raudive’s book, he laid out the early groundwork for classifying EVP, which he dubbed as “Microphone Voices”:
Group A: Consists of voices that can be heard and identified by anyone with normal hearing and knowledge of the language spoken; no special training of the ear is needed to detect them.
Group B: Consists of voices that speak more rapidly and more softly, but are still quite plainly audible to a trained and attentive ear.
Group C: Unfortunately, these can be heard only in fragments, even by a trained ear, but with improved technical aids, it may eventually become possible to hear and demonstrate these voices, which lie beyond our range of hearing, without trouble.
This classification of EVP stood for only a short while. An American, Sara Estep, plunged headlong into recording and documenting EVP. Eventually she founded the American Association of EVP, or AA-EVP, in 1982 (which has since been renamed ATransC since Tom & Lisa Butler took over in place of Sara). Once the organization had begun in earnest, a new classification system was needed and has since been adopted by paranormal investigators and is now the scale for EVP measurement used globally.
Class A: Voices can be heard and understood over a speaker by most people. The average listener will hear what you you expect them to hear without prompting. Loud does not equal Class A.
Class B: Voices can be heard over a speaker, but not everyone will agree as to what is said. The average person will hear what you expect them to hear with prompting.
Class C: Voices must usually be heard with headphones and are difficult to understand therefor it is usually a vain effort to present these types of EVP as evidence to anyone other than the researcher.
Recently, since audio recording software has advanced significantly, researchers have found that sometimes there are EVP’s that are obtainable by playing an EVP backwards. This is normally done when an EVP has a tone and cadence (and possibly waveform) that is out of the normal range of EVP’s for that session. If played backwards and an EVP exists, it is classified as an EVP-R. This classification has not been adopted by ATransC as accepted EVP evidence as of yet.
Several paranormal researchers are now utilizing EVP-X as a way to describe recordings taken from audio generating devices such as the Ovilus, EVP-Maker, or a Ghost Box. This classification also has not gained acceptance by ATransC as suitable for the EVP scale.