Here is an interesting blog I found where someone recorded themselves sleep talking and you can listen! http://dansleep.blogspot.com/

People who have slept in the same room as me claim that I talk in my sleep. Now that I am wanting to keep track of dreams using a voice activated tape recorder, I am going to find out what I say when asleep. The first time I found out how much I moan, and that the alarm really did go off after an hour nap, and that I never heard it....I slept nearly three hours for the nap. The most intelligible thing people say I have said in my sleep is the phrase "rip up grass outside." Do you talk in your sleep? Have you ever said anything that anyone else could understand? I taped my sister talking in her sleep once, and played it back to the neighbors, when I was a teenager. Oh boy, was she mad! She put water on the floor in revenge, and I slipped on it and hit my back really hard. And she was the one who got in trouble. But seriously, some of the unintellible things I always wonder if I could find a way to play them backward, if they would mean something!