If it's just the quiet/noise reduction you're after, you could have a look at noise blocking earmuffs used in construction/workshops and such. Those are designed to do one thing, and one thing only, and that is to reduce the ambient volume as much as possible. Being comfortable to wear for long periods at a time is usually higher on the list of design goals too than with regular headphones, so it might be easier to find a pair that, ideally, you forget you have on after a while. And you won't have to worry about cables getting in the way, or batteries needing to be replaced and such.
One trick I'd like to add, in terms of wearability, is changing the coverthingies (don't know what they are called) that come in contact with your head. That's one variable that can be adjusted, if you find otherwise perfect headphones. There are some materials I really can't stand and things like leather tends to get warm and sweaty after a while. For my headphones I use at home I cut up some soft old socks and wrapped those around, which not only makes them feel a lot more comfortable to wear, it also adds to the amount of noise they block (passively). Since I didn't use the same socks on both sides, it's a little easier to tell apart which side is left and which side is right too.
One more option would be to have a look at a musical instrument store. There are special headphones designed for drummers for example, which should do a better job at passively reducing the volume.
Anyway, as wyverary mentioned, best to look around a lot and try lots of pairs. Every head is different, so what's comfortable to one person can be agony to wear for the other.
Edit: for the noise blocking earmuffs I suggest having a look at specialized retailers selling tools for stone cutting companies (the ones that take big boulders of marble and such and cut them into slabs for example), or go to one of those workshops themselves and ask what they use. It's a continuous very high volume environment; they need the good stuff when it comes to blocking noise all day long.