EVP -
Electronic Voice Phenomena 
EVP are mysterious voices caught on tape of no known origin. Usually caught on audio tape, the disembodied voices are usually not heard at time of recording, but found later upon review. You can also get strange sounds which PITT refers to as SA's or Sound Anomalies. They come in may forms and here we briefly describe the basics. Thomas Edison first introduced the concept of EVP and shared with the world his findings on his stenograph. EVP is said to be in the lower sound waves which are not audible to human ears. Humans generally hear sound waves that are in the 20 to 20,000 Hz cycling range. EVP's are commonly lower than this and usually captured in the ELF (Extremely Low Frequency) range of about 30-300 Hertz which is impossible for the human voice to cycle at. Frequecies are measured in cycles per second....
1,000,000 cycles per second
Megahertz (MHz)
1,000 cycles per second
Kilohertz (KHz)
1 cycle per second
Hertz (Hz)
EVP varies greatly and some are more easily heard and understood than others. They differ in age, gender, tone and emotion. They are often sigle-words, phrases and short sentences and sometimes they are just random noises such as grunts, growns and growling.
Classifications OF EVPs
- Class A EVP
- A class A EVP is very easily heard and understood by everyone. They are usually the loudest with the words or phrases leaving little dispute over what is being said. Very clear and loud audio capture is obtained in a class A EVP.
-
- Class B EVP
- Class B is much like Class A but some words may be warped or inaudible, but you can clearly hear them. Class B is the most common type caught. Certain syllables are jumbled and not as easily determined as Class A EVP's.
-
- Class C EVP
- A Class C EVP is faint and usually the lowest in volume, such as whispers. It is not uncommon to be unable to determine words or phrases in this class. It tends to be the hardest to understand and sometimes not heard by everyone leaving much dispute.
