Another problem I have personally felt that doesn't get discussed much at all is the overpressure effects on your eyes. Good to see the mastoid bone mentioned above.
I have tinnitus pretty bad as well. When I put my good ear down on the pillow, I can still hear sounds in it where the left side knows there is a noise impulse being detected with others means and what's left of the left ear, but has formed different neuro connections with the right ear to validate the sound as a compensatory mechanism. It sounds like clicking, which is annoying as hell. My little boy has one of those poppers too, which is especially fun.
I have tinnitus pretty bad as well. When I put my good ear down on the pillow, I can still hear sounds in it where the left side knows there is a noise impulse being detected with others means and what's left of the left ear, but has formed different neuro connections with the right ear to validate the sound as a compensatory mechanism. It sounds like clicking, which is annoying as hell. My little boy has one of those poppers too, which is especially fun.