Trance vs sleep?

[geekdh]

I consider it a trance if I’m listening to the induction,relaxed, and focused on his speaking, and I just sort of “zone out” and can’t remember the last few minutes of what was said. But my problem that I do that fairly often, only to pop back up a few minutes later.

So how long do you have to stay under for it to really be a trance? All the way to the end of the file? And if you don’t come out at the wakener, were you truly in trance, or did you just fall asleep?