Hey CosmicIron,
I'm testing this technique for 30 days, and writing down results of each day.
I'm at the day 2 now. When I did the SSILD, It felt like I've been doing it for like one hour. It was because I think I felt asleep during second cycle and then woke up, and finished 3 more.
Later then I had feeling that I can't fall asleep, but it was FA I believe. And suddenly I woke up for real, still being calm and relaxed, I started hearing high pitched noise in my head. It wasn't distracting at all. It sounded like this:
Zippyshare.com - hi pitch.mp3
I think I misread your post, and I started to concentrate on that noise. It faded away.
What was that?