Hrm.

It doesn't look like they actually differentiated or isolated... basically listening to something like a history podcast or relaxation, ambient audio track, with no actual visual component... unless I'm missing something.

I very often have trouble getting to fall asleep without... some kind of calm, soothing audio.

With something like that, I'm usually out cold within 15 minutes.

Without it, I can stay awake for hours past the time I actually want to go to sleep.

I'll just play it over speakers at a low volume, or use earbuds.