As with eyeglasses, if too-tight fitting, they can cause physical discomfort.
you don't say anything just pull their headphones out of their ears. Or if you're looking for a more polite approach just tap them or yell near their ears. :)
to put headphones on your ears is to put the left side of headphones is put headphones away from your ears
no
Supra-aural headphones are headphones that sit directly on the ears instead of enveloping them, which is what circumaural headphones do.
Because it hurts and it breaks your eardrum when something such as a stick goes in your ear
If you have smaller ears, you should get the ear bud type headphones that will fit directly into your ear.
MDR 7506 Sony headphones are fairly comfortable on your ears. They are fairly expensive, high-end headphones and thus demonstrate superior design and comfort.
Ultimate Ears headphones come in just about any color you can find in this universe. Everything from white to black to blue and yellow. They even have glow in the dark headphones.
3 hours straight is not good but it won't ruin your ears. Try not to listen to headphones all day. This will hurt your ears.
Headphones
9000
A good thing to look at is what kind of headphones are water resistant (because of sweat) and can handle the high level of movement your body is doing. Look for headphones that have ear clips so it helps to stay on your ear, then look for the extra cushion so that sweat isn't directly going to the headphone (and it hurts your ears less).