What if you wake up right at start of REM cycle? Do you continue where you left off in the REM beats or is it necessary to start over as you try to fall back asleep? This stuff works. I had only 10 minutes of deep sleep but it was deep and the beats put me in sleep paralysis. But when I finally came to I actually felt well rested.
Normally, if I wake up at the end, I just take off my headphones, turn off my device, roll over and go back to sleep :)
nidusaquilae76