Paul,
That was a good bit of info, discouraging a bit, but informative. It is making me re-evaluate my thinking on the subject. When I went to this method of learning, listening to the tapes wasn't the only thing I changed. Not taking notes and really absorbing the lectures (as previously mentioned), trusting my instincts more when answering questions and just the fact that I usually hear the complete sound file once before actually falling asleep could be the primary contributors to my success thus far. At any rate it has helped and I am not completely discouraged.
I will try to do everything the same but only let the sound files play once instead of looped. If there is no difference then it would support the studies provided in Paul's post, that sleep learning isn't an easy or effective process, or at least it isn't what has enabled my success. If not I will continue my own experiments. I will post my results.
When using these audio programs it is best to use an 11k or 22k sampling rate at 16 bit stereo. A high sampling rate really sucks up computer resources and can take up to 200+ megs of disk space per file. 11k and 22k also gets rid of the tape hiss but reduces the background sounds, crashing waves. If anyone has any positive or negative results with this please post them. Thanks.
Jeff