There are four different classes in which to categorize your EVPs into.  The classes are titled A, B, C, and R, EVPs.  The explanation on how to categorize your EVP into the proper class is listed below.

CLASS - A

          For an EVP to receive a Class A rating it must be a very clear voice and everyone that you let listen to the recording agrees on what is being said by the ghost or spirit.  Everyone who hears the voice must come to the same conclusion about what it is saying without being told by another investigator.  These voices do not need to be amplified or cleared up using a computer, sound editing program but can be clearly heard straight from the recording devise.  It does not have to be extremely loud but it must be clear on what is being said. The Class A EVPs are the best voices of the dead captured and are the rarest to record.

CLASS - B

          An EVP that can be understood and most people agree on what is being said will fall into the Class B, category of EVPs.  These EVPs might not be understood by everyone who listens to them and might even sound like it is saying something completely different to other people that listen to the recording.  This class of EVP might need to be amplified using a computer and a sound editing program before they can be clearly understood.  To get a Class B rating the voice must be fairly clear and easy to determine what most of the words are,  when analyzing the voice with your computer.  This is the most common class of EVP captured!

CLASS - C

          The Class C, EVP will be the worst quality voices that you can capture.  It is nearly impossible to understand what is being said even with the help of computer enhancement. These EVPs are often just whispers or mumbled words or might even sound robotic.  The Voice cannot be understood but the investigator still knows that it is an EVP because of the fact that no one was talking during the recording session and human sounding voices can clearly be heard in the background noise.

CLASS - R

          In order for an EVP to receive a Class R rating it must have a meaning to it when played in reverse.  Some EVPs will have a meaning when played normally and a different meaning in reverse.  When this happens it will have two classifications.  For example a Class A, EVP with a excellent and clear meaning in reverse as well, would be titled a Class A-RA,  EVP.  This meaning it was very clear to understand both forward and in reverse.  It can not have a Class A-RC because this would mean that it could not be understood in reverse which would not be a Class-R EVP.  You may have a Class B-RB or a Class A-RB ect.