Audio Engineering: Paranormal EVP Analysis – Ohio State Reformatory

Audio Engineering: Paranormal EVP Analysis – Ohio State Reformatory



A technical analysis of a suspected Electronic Voice Phenomenon (EVP) recorded at the Ohio State Reformatory, Mansfield, Ohio. Analysis shows three stages of progressive audio processing: the original clip, an enhanced version, and one with an aggressive spectral de-noise effect applied.


Oftentimes we compare sound utterances under investigation to known examples. In this case, we compared the clip to a known male voicing of “fuck you.” (See comparative spectrograms in the video).

Here’s what we found:

Similar voice intonation pattern for the utterance: Forceful initial rise and lower pitched trail off.

Frequency response curve and formant range consistent with male voice Starts at ~1.5kHz and trails off at ~300Hz.

Also, as demonstrated by brightness on the spectrograph and diminished aural loudness in relation to the researchers near the recorder, the voicing source appears to be distant from the microphone (i.e., not within the near field pickup pattern of the microphone).

This is the first time we’ve ever made a sociolinguistic assumption about a possible EVP. The voicing is suggestive of the “inland north” dialect common among residents of northern Ohio, including Cleveland, and Akron regions.

The suspected EVP strongly appears to be a male voicing of the phrase, “fuck you,” an idiomatic expression of anger, defiance, or contempt toward another.

The dialect appears to be consistent with that of a speaker from northern or northeast Ohio. This would be consistent with the location of the reformatory.

The source of the voice appears to be distant from the researchers, perhaps originating in another room or elsewhere on the premises. It is reasonable to conclude that this phenomenon is not a random acoustic or audio equipment artifact (noise).


As to whether this is a legitimate EVP, the acoustic evidence does not confirm or refute that assumption. However, it does strongly suggest that this phenomenon is not a matter of pareidolia (i.e., interpreting random sounds as voices in one’s own language) or apophenia (i.e., perceiving patterns in random aural information). This is real.

Therefore, based on the evidence it can be assumed that someone (or something) did, in fact, exclaim “fuck you” coincidentally or in direct response to the researchers’ investigation. As for the source, the acoustic evidence suggests that the utterance could have come from someone else (a male) on location, perhaps in another room or down the hall from the researchers.

However, the acoustic evidence does not rule out that this is, in fact, a paranormal phenomenon. If this is an EVP, it would be on the low side of Class A.