Seeking EVP Examples for Study

by Tom Butler
See: The Energy Profile of Transform EVP

ATransC is seeking examples of Transform EVP that can be compared to supplied background sound so that the difference in waveform can be clearly demonstrated.


It is well-known that EVP are formed by transforming available audio-frequency energy to produce the intended voice. Current theory holds that the transform process is the result of stochastic amplification occurring in an active component of the recording device–probably a transistor junction.

If the voice in EVP is formed from background noise, then there should be a detectable difference between input and output of the stage of the recorder in which the transform is thought to occur. For a digital voice recorder, that would be between the microphone and before the memory circuit. A way to test this theory is to use recorded sound as a known background source and comparing the resulting EVP sound file with the same part of the supplied background sound file.

This study is in two parts. In the first phase, the examples provided by website visitors should provide a collection of “convincing” transform EVP examples. Second, for Phase 2 of the study, if a sufficient number of convincing examples are collected, a research facility will be asked to analyze the examples in an attempt to identify possible anomalous differences in energy profiles between input and output files.

Phase 2 of this study will be expensive and sufficient funding has not been arranged at this time, so Phase 2 will be pending good examples and sufficient funding. Also, it is likely that examples will be needed that have been recorded under more controlled conditions. Assuming this is the case, Phase 1 of this study should be considered an interview process to select practitioners who are more likely to be able to produce additional examples.


You are asked to either use a pre-recorded background sound source or use two recorders.

Once an EVP is recorded that is able to be correctly understood by at least two people without prompting, the sound file containing the EVP with a few seconds of sound file before and after the utterance should be saved with sufficient labeling to distinguish it from others, as: (c)your_name_year-title. For instance: (c)butler2012-compare_transform.mp3

A second file should be saved containing the the portion of the background sound file associated with the EVP example. It is important that a third file be composed, as in the example above, so that both input and output files can be compared as synchronized sounds.

Practitioners wishing to participate in this study should use the contact form at the bottom of each web page to inform us that you wish to send in an example. You will receive the email address to use with our response.

You will retain ownership of the example sound files, but will be asked for permission for use of the sound files for the study, and potentially, in articles on this website. ATransC will require your real name, but you may remain anonymous beyond that. ATransC does not share personal information without specific permission from the person.

Participants need not be a ATransC member, but as always, you are encouraged to support the organization via your membership and donations if you think this kind of work is of  value to the the study of these phenomena.

Hint: It is useful to add some form of marker in the supplied sound file as a beacon so that the input and output files can more easily be synchronized. This is especially important if a steady-state input file is used, such as white noise.


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