Do we need to loop the sound until we wake or is the 90 minutes sufficient, I fall asleep fairly quickly, but wake often which deprives me of deep sleep. I do dream a lot though.

I'm going to try this tonight, fingers crossed I'll wake up feeling refreshed..
With this track, you should normally be asleep within 20 minutes. After the video ends, just sleep naturally for the rest of the night.
Stefan Mansukhani