I fall asleep regularly wearing headphones - I mean going to sleep for the night - and
have a few observations that others might find useful.
1. Headphones worn in bed risk ending up on the floor, being rolled over upon,
and sundry other unpleasantries. They need to be reasonably sturdy.
2. I prefer closed headphones in this situation - might as well keep out any outside noise
when falling asleep.
3.. Avoiding phones that have large earcups.
If they do, they'll rub against the pillow and be microphonic.
(For this reason, I wouldn't consider wearing the AT 700's.)
4. Clearly, headphones worn while lying down must stay in place - and I've found few that reliably do so.
Having tried many, many headphones, I know that few can be worn while one is horizontal.
Grado's are very good in this regard.
But they're sort of delicate. And open, of course.
AT ATH-M50's slide right off.
so do Shure 840's.
Beyer DT880
Ultrasone 780
Denon 2000
and several others.
Wthout listing all of the headphones I've tried this with, I'll mention the two that work best for me:
Senn HD25 I II - they stay in place, sound great, and the earpieces are small enough to avoid touching
the pillow (or whatever you've got you're head resting on...)
The other pair - Sony MDR 7606 / MDR V6.
They stay in place, earpieces are small enough front to back, and sound is
pretty decent especially when the intention is to be asleep in a little while.
And with the Sony's, if there is any untoward event, well - they're pretty inexpensive.