Ordinarily, EVP's are obtained by those who try and communicate with the dead by means of a recording device (intentional paranormal research). The recipients of phone calls however, are seldom involved in paranormal research. There are numerous documented cases such as these from all over the world and they seem to fall into three categories.
1. The call is from a person who has just recently died. Occasionally, the person receiving the call does not know at that time that the caller is dead and believes he/she is talking to the living person.
2. The call is an urgent message from a friend or relative who explains that they are placing the call for the deceased. Later, the recipient learns that the friend or relative never made the call, although he or she thought about doing so. The phone voice will often mimic that of the living person perfectly. However, a few recipients have described these voices as mechanical or flat.
3. A phone call and conversation with the person whom the caller later discovers was dead at the time the call was placed.
Many years ago I received a phone call from an older lady. It was a very bad connection and sounded far away. She gave me her name and asked to speak to Robert. When I told her she had the wrong number, the woman seemed confused. She said she needed to tell Robert something and could I please go get him. I politely told her again that she had the wrong number. Eventually, she hung up. Later, I mentioned the phone call to a neighbor of mine. She got a funny look on her face--the name the older lady gave me was someone who had died in the house many, many years ago. Robert was her husband and had passed away six months after his wife. I thought this was odd because my phone number would have not been known by the old lady or anyone in her social circle.
Unfinished business? Explainable? If it was a message from the other side, I wish I could have helped in some way. I guess I'll never know.