Undulating sound?

[Hfeline]

Hiya.  It's been a while.  I have been diligent, and reading slow to take in better, but I have yet to project.  One thing I do nightly is write out, "I am having and Out of body experience" twenty times, and I am adding new routines to my days as I adjust to the old one.  Anyway, report done.  This is what I'm here to talk about.

I was watching Unsolved Mysteries a few weeks ago and there was some screwup with their machine.  The sound still played, but it was undulating.  Sort of: Woomp. Woomp. Woomp.  Anyway, before getting through the one episode, I was fighting to stay awake.  I recorded the next episode to watch after work and it was the same, and I was fighting to stay awake again.  I've heard about research on this, Hemi-Sync, right?  Like Rain drops, even though rain doesn't really cause me to fall asleep.  I was thinking of using the sound to play over a self-hypnosis CD, but I deleted the recording already.  But I was wondering if there is a resource available where I could listen to a few and find what would work really well for my purposes.