Digital Voice Recorder
Electronic Voice Phenomenon



Ghost Hunting Equipment: Digital Voice Recorder
Electronic Voice Phenomenon

Electronic Voice Phenomenon are considered to be voices of the dead which are captured by means of technology such as digital voice recorders. There are different classes of EVPs which are used to rate the quality of the EVP recording. These classes Usually range from Class A to C but some investigators take it a step further and Class EVPs from A to G.

Digital Voice Recorders are used to help further evidence of spirits by recording what is called an Electronic Voice Phenomenon or EVP.

An EVP is defined as: a voice or sound that is picked up an electronic device which was not heard by human ears. This type of noise is only heard through technology such as a digital recorder and never live (in real time) from a human ear.

EVP's may provide further proof that there is some form of energy attempting to communicate. EVP's can be random noises, voices and in even some circumstances they can be responses to physical questions.

The Journal of the Society for Psychical Research published a report by paranormal investigator Alexander MacRae. MacRae conducted recording sessions using a device of his own design that generated EVP.

In an attempt to demonstrate that different individuals would interpret EVP in the recordings the same way, MacRae asked seven people to compare some selections to a list of five phrases he provided, and to choose the best match. MacRae said the results of the listening panels indicated that the selections were of paranormal origin.


Creating EVP through Ultrasound

This clip demonstrates how to fabricate Electronic Voice Phenomena through modulated ultrasound, without manipulating the recorder or the recorded sound files.

It is shown how to prepare an inaudible ultrasound sample and then record that sample with digital and tape recorders, making it audible again. The approach presented here is based on digital aliasing and nonlinear distortion.

Portable digital voice recorders are currently the technology of choice for EVP investigators.

Since these devices are very susceptible to Radio Frequency (RF) contamination, EVP enthusiasts sometimes try to record EVP in RF- and sound-screened rooms.


Nevertheless, in order to record EVP there has to be noise in the audio circuits of the device used to produce the EVP.

For this reason, those who attempt to record EVP often use two recorders that have differing quality audio circuitry and rely on noise heard from the poorer quality instrument to generate EVP.

Some EVP enthusiasts describe hearing the words in EVP as an ability, much like learning a new language. Skeptics say that the claimed instances are all either hoaxes or misinterpretations of natural phenomena.

EVP and ITC (Instrumental Trans-Communication was coined by Ernst Senkowski in the 1970s to refer more generally to communication through any sort of electronic device such as:

tape recorders, fax machines, television sets or computers between spirits or other discarnate entities and the living)
are seldom researched within the scientific community and, as ideas, are generally derided by scientists when asked.

There are a number of organizations dedicated to studying EVP and instrumental transcommunication, or which otherwise express interest in the subject. Individuals within these organizations may participate in investigations, author books or journal articles, deliver presentations, and hold conferences where they share experiences. In addition organizations exist which dispute the validity of the phenomena on scientific grounds.

The Association TransCommunication (ATransC), formerly the American Association of Electronic Voice Phenomena (AA-EVP), and the International Ghost Hunters Society conduct ongoing investigations of EVP and ITC including collecting examples of purported EVP available over the internet.

The Rorschach Audio Project, initiated by sound artist Joe Banks, which presents EVP as a product of radio interference combined with auditory pareidolia and the Interdisciplinary Laboratory for Biopsychocybernetics Research, a non-profit organization dedicated studying anomalous psi phenomena related to neurophysiological conditions.

According to the AA-EVP, it is "the only organized group of researchers we know of specializing in the study of ITC.".



- Electronic Voice Phenomenon - 




Classes of Electronic Voice Phenomenon (EVP Classes)

Class A - This form of EVP is the best class out of all the EVPs. It is clear and loud and is very easy to understand the communication involved during the recording. Class A EVPs are usually involved with direct questions being asked which means the haunting is an intelligent form.

Class B - This form of EVP is the most commonly captured EVP. It is still clear and loud but not as clear as a Class A EVP. There is usually some static and background noises involved during the capture of the EVP. There usually has to be some form of enhancement with the EVP such as increasing the decibel levels and/or using a filter to clean up the static noise. This type of EVP is usually not involved with direct questions being asked.

Class C - This is usually considered the lowest quality EVP that can be captured. Using enhancements and/or filters may not be able to help clear up the EVP at all since it is of such low quality. Sometimes paranormal investigators will argue if it is even an EVP at all.

* For most paranormal investigators there are only three classes of EVPs but some investigators include extra classes of EVPs which include Class D and Class G EVPs.


Class D
- This class is sometimes referred to as Class R. This class is considered to be extremely poor in quality which usually involves loud hissing and background noises and any type of voices are inaudible. This class cannot be used as evidence of the paranormal because of the low quality.


Class G - This form of EVP is completely useless. There is so much distortion and background noise that it cannot be used as evidence of the paranormal. Even if enhancements are done on this class of EVP the quality still lacks and it is still questionable if it is considered even an EVP at all.




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