A Two-Year Investigation of the Allegedly Anomalous Electronic Voices or EVP

by Anabela Cardoso
Republished from NeuroQuantology | September 2012 | Volume 10 | Issue 3 | Page 492-514
Please see the entire article at NeuroQuantology.com


A relatively novel acoustic phenomenon has inundated the Internet and specialized literature. Several Associations, some of them with an important number of members, have formed around it in many countries. In the Anglo-Saxon world the phenomenon is called EVP (Electronic Voice Phenomenon) and is usually assumed as electronically mediated communication from or with the deceased. The first tests aimed at verifying the reality of these claims were carried out in Sweden and in Germany, in 1964 and 1970, under the direction of Professor Hans Bender from Freiburg University (Bender, 1970; 1972; 2011). The present report describes in detail the tests designed to record the allegedly anomalous electronic voices, or EVP, under controlled acoustic conditions. Series of experiments were carried out in Vigo, Spain throughout a period of two years under conditions controlled to the highest degree achievable. Several operators were involved in the many tests conducted in Acoustic Laboratories and professional recording studios equipped with very high levels of acoustic shielding. The protocols and procedures followed in the experiments, as well as the results obtained, are herewith described. Several extra voices were recorded during the many experiments performed for which no normal explanation was found.


The reality of the apparently anomalous electronic voices was confirmed in acoustically controlled environments with different operators.

With the exception of the June 17, 2008 radio voices, none of the voices or whispers described in the present report were heard live during the tests. Extra voices, originating from undetectable sources, were identified in the following situations:

  1. Under controlled speech and controlled acoustic environment – AC as sole operator at the Metropolis and at the University of Vigo; Iñaki at the University of Vigo and at the Metropolis.
  2. Under controlled acoustic environment and uncontrolled speech – AC, Portuguese operators and participants (PN and Francisco) at the Metropolis; AC, IH and UH at University of Vigo; the same and Iñaki at the Metropolis.
  3. Under uncontrolled speech and uncontrolled acoustic environment – AC and the Portuguese operators outside the Acoustics chamber of the Superior School of Engineering; AC and Iñaki at the same place.

The voices seemed to benefit from the presence of noise in the environment (particularly human speech and metallic clicks). The very few voices recorded without any explicit noise had quite lower amplitude than the voices registered with a background of explicit noise. The amplitude of the voices seems to be related to the level of background environmental noise extant in the room when the voices appear recorded. Probably to other variables, too but those remain undefined and need further research.

The voices were louder, clearer, more abundant and flowing when uncontrolled direct human speech by two or more people prevailed, independently of an acoustically controlled or uncontrolled environment. Above all, they seemed to benefit from a situation where the operators’ frame of mind was lively and energetic, and perhaps also from a relaxed and friendly atmosphere. On the other hand, they seemed to be negatively affected if the operators were focused on the experiment.

The voices seemed to benefit from a slightly chaotic situation – AC, Portuguese operators, PN and Francisco at the Metropolis; AC, IH, UH and Sound Technician ML at the Laboratory of Acoustics. The voices did not seem to be significantly more abundant when an artificial basis of human speech was used (Psychophone* and EVPmaker) as acoustic background source.

Methods, the psychophone and the EVPmaker software methods proved to be highly unreliable, not because they are particularly bad acoustic backgrounds for the production of the voices but because they are undoubtedly a source of uncertainty and ambiguity in the analysis of the results. They can very easily originate pareidolia and/or projection of meaning based upon expectation. Very particularly with the EVPmaker software, it is easy to find “results” in recording-sessions where they do not exist. In addition, an erroneous interpretation of the content of possibly anomalous utterances found in the recording is very likely. Most of the EVP “results,” published in the Internet, fall into one of these categories.

The equipment and location of the experiments did not seem to weigh on the formation of the voices but the highly sensitive microphone Bruel & Kjaer used at some of the University experiments appeared to capture more voices than the other microphones.

The content of all the voices recorded in the tests, with the possible exception of “altus”, were pertinent to the situation and/or to the operator(s)

From the results of the present research, this author fully corroborates Professor Alex Schneider, the Swiss physicist from St. Gallen who closely followed, studied and replicated some of Raudive’s work, when he declares in his Appendix to Breakthrough:

“Other investigators choose the moment when a transmitter starts to beam out the carrier wave just before beginning to transmit a program or else they select a slow-speaking lecture program in which the pauses between groups of words are so considerable that call signs can be interspersed. A carrier appears to be necessary, or, at any rate, desirable… a number of voices sound as though they were constituted from the homogeneous noises spectrum by some physically unexplained process of selection” (ibid, pp.340-341).

Moreover, in view of the results, a pertinent question is to find out if there are parallels between the allegedly anomalous electronic voice phenomena and so-called paranormal events of a different nature. Apparently, one of the distinctive characteristics of paranormal events is their occurrence in situations when they cannot be easily controlled. Professor Hans Bender is quoted as saying (translation):

“If we tentatively admit the still questionable factuality of ‘spooks’, then [the attempt] to keep hold of it by photographing, filming or by recording acoustical phenomena will have to face the difficulty that the phenomena apparently elude a critical grasp. The impression almost suggests that the intelligent forces mock the observer and produce a phenomenon just there where one cannot get hold of it” (Bender, 1979).

* Editor: A psychophone compares well as an early form of radio-sweep.

draanabela-cordosoAnabela Cardoso has published the ITC Journal (itcjournal.org) since March, 2000. She is amongst the few ITC practitioners in the world able to communicate using Direct Radio Voice (DRV). Since 1998, she has communicated with an etheric communication station which identifies itself as Rio do Tempo (Timestream).

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