The Electronic Voice Phenomena or (EVP), was first discovered by a Swedish Opera singer Friedrich Jürgenson in 1959.  Jürgenson had purchased his first reel to reel audio recorder to record some of his singing performances. Jürgenson who was an accomplished Opera singer, effectively, and without prior knowledge, captured voices within the recording sessions he had taped. Furthermore, he had also captured occurrences during other numerous recording sessions where he was attempting to capture birdsong using the same reel-to-reel tape recorder. When he replayed the tapes, he heard faint but intelligible voices in the background, even though there was no one else in the vicinity when the recordings were made. By repeating the procedure, Jürgenson found that the EVP occurrences could be reliably replicated.

  At the following link, you can download Friedrich Jürgenson's book "Voice Transmissions With The Deceased" The book is in Adobe Acrobat format. To listen to one of Friedrich Jürgenson's own musical compositions, click here Ist das Liben Traum oder Wirklichkeit?

    Taking their inspiration from Jürgenson's findings, other individuals subsequently investigated the EVP phenomenon such as the German parapsychologist Hans Bender and by the Latvian psychologist Konstantin Raudive. Following the publication of Raudive's book on his research (Breakthrough, 1971) these phenomenon's are now often referred to as "Raudive Voices".

 As we have seen through a timeline of history, the phenomenon known as the "EVP"  or ( Electronic Voice Phenomenon )  has been studied by many an individual and has baffled many with it's peculiarly strange aspects. Many different groups and individuals have studied this specific phenomenon including Scientists, Physicists, Engineers, even the Vatican has had an interest in the phenomenon. To review a small exert regarding the Vatican's findings, click here Science, Religion and the EVP .

  The average "EVP" can be fairly easily recognized and usually lasts only a matter of seconds. The average duration of an "EVP" is usually within (1 to 2) revolutions of the cassette tape, or approximately ( 1 to 2.5 ) seconds.  "EVP's" often leave behind a very specific flavor  or characteristic which makes it's occasion stand out from the average evident sound wave. One can easily recognize an "EVP" by it's ever so prevalent "Echo" or "Oscillating" sound characteristic.  An "EVP" occurrence rarely sounds like that of any other evident sound wave which is gathered during a recording session. An "EVP" occurrence often displays an oscillation or fluctuation of it's level of frequency. What I mean by this statement is simply this. The average "EVP",  which most often occurs on the lower end of the frequency spectrum, displays a true fluctuation in it's level of frequency. For an example of this principal, let's say that we have recently obtained an "EVP" occurrence during a recent excursion to a local cemetery. Being that we are planning on utilizing this piece of data for testing purposes, we will name this piece of data "Example A" . Now, let's look at  "Example A" for it's evident properties. In a measurement of time, we have noted that "Example A" displays a time duration of 1.2 seconds. Now a duration of 1.2 seconds is not a large increment of time, so we must assume that only a small amount of data can be audibly passed through or transferred on that wave length in such a short measurement of time. If you were to take "Example A", and pass it's 1.2 second sound wave through that of a Spectrum Analyzer, you will note that "Example A" now visually depicts it's activity through that of a graphical wave or spike. In this graphical wave or spike, you will note that "Example A" displays a low point, a middle point and a high point within the spike itself. In each noted point of the spike, the Spectrum Analyzer will display a level of frequency. In reference to the mentioned points within "Example A", we note that the low point of the spike measures a frequency reading of 20.6hz., the middle portion of the spike displays a frequency of 24.2hz and at the high portion of the spike displays a  frequency reading of 27.9hz. These collected measurements within "Example A" display the variation of frequency within the occurrence and furthermore prove the relevance of the fluctuation theory. I do hope that this provided example clears up any confusion regarding the theory of fluctuating frequency.

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