Do Graveyard tapes reveal the existence of Ghosts?

Years ago the famed paranormal show In Search of with Leonard Nemoy ran an episode about taping the "voices" of spirits. This was 30 years ago of course so I don't remember the details, but the idea was take a tape recorder to a graveyard and make some recordings. When you play it back, do so at slow speed and you'll hear the voices of the dead.

Being young, fresh out of high school at the time, when a friend saw the episode and suggested we do it ourselves several of us agreed with enthusiasm. So we grabbed some cassette tapes and a recorder, and headed off to a mysterious graveyard built at the turn of the century. 

The cemetery had two parts: an older area adorned with large statues and gravestones, and a newer area that was flat and open grass, with plaques on the ground instead of traditional gravestones. We went to the new area, walked in some distance, put the recorder down, then went back to our car and waited for 45 minutes. 

We picked up the tape and brought it back to the car. We placed it into the cars tape player and listened, but didn't hear much of anything-just a few clicks. It turned out that the batteries on the cassette player were low so the recording was slow. To remedy the problem, we went to a friends house and played the tape there on the original recorder.

What we heard was astonishing. A few minutes went by, and then we heard what can be described as two rocks being hit or smashed together. This occurred in a sequence of three: BANG! BANG! BANG! Remember-the recorder was placed in an open grassy area. Not to mention while waiting by the road we were watching the location, and nobody approached the recorder-in fact there wasn't a (live) soul to be seen anywhere we could see.

So a few more minutes went by of silence, and astonishingly we heard a voice! It was a man speaking. You may find it hard to believe but I assure you its what I heard with my own ears:

ST. PETER, LEAVE ME IN PEACE

Wow this was way more than we had bargained for! We listened to the tape several times, chills running up and down our spines. I went home scared to death. I couldn't sleep that night, and can still see the moonlight that came through the window at 2 AM as I kept replaying in my mind what I had heard on the tape. 

The following night another friend was told of what happened and was astonished. He wanted to duplicate the event, so once again we suited up with a tape recorder and headed off to a cemetery-this time a different one. It was December and that night it was very windy. We left the tape recorder by a grave and waited for 30 minutes, then brought it back to play in the car. 

This time, there was silence for a few minutes, but then....we heard the same sound of rocks smashing together. This time it started softly, as if two rocks were barely being touched...click, click, click. It went on for a good 10 minutes, gradually getting louder....click, bang, BANG! Finally it got very loud as if two stones had been smashed together as hard as could be. Then the sound got lighter again, gradually diminishing for a minute or so followed by silence.

There were no voices this time, but the similar sound of rocks being hit together was very intriguing. Later someone who had seen another episode of In Search Of reported that if you slowed the tape way down, the clicks or smashing sounds would turn out to be voices. But we were scared out of our wits, and threw the tapes away.

Do you believe? What are your ghost stories?