When someone goes to read about or buy a new pair of headphones, they may be somewhat confused about how companies seem to interchange, or at least not explain their fancy terms of design, but just throw them around with abandon.. Hopefully, this might help.
There are basically three kinds of headphones that are worn outside the ear, they are: Over the ear, circumaural, and supra-aural.
Circumaural headphones completely block the external part of the ear from everything around it. Circumaural literally means, surrounding the ear.
Supra aural headphones rest on the ear, and usually do not cover the ear as completely as circumaural models do. Their ear-cups are also not as large. Supra aural headphones are also often considered not as suited for professional work, but more for casual or mobile listening.
Over the ear headphones can be both Circumaural or supra aural models. Basically, they are any model of headphones that have a band that goes over the head. also, Circumaural headphones can be either open or closed back, depending on the model. Supra aural models can be closed back though they don’t completely surround the ear, so they are more prone to sound leakage, though that also means they are more naturally transparent to environmental sounds around the listener. Some might call closed back supra aural models more semi-closed or even semi-open.
Open back headphones sound more natural. There are openings behind the speakers in the ear cuts for air to move through. This means that low frequency resonances don’t build up like in closed back models. It also means that what you’re listening to through open back headphones will probably leak out more and may annoy people around you. They’re still my favorite though, and are great for focused listening in a studio or at home. They’re also great for professional work and at times more preferred by audiophiles.
Closed back headphones are completely closed in, only allowing sound from the speaker drivers to be heard inside the ear cups. People around you, especially in quiet spaces will appreciate when you wear them. I used to strongly dislike closed back headphones, because being totally blind, now I was also aurally insulated, but now with transparency mode being included in recent models, wearing them doesn’t bother me anymore if they have it.
In ear models, often called earbuds don’t have any band going over or behind the head, so are much less visible than their larger counterparts. They also take up much less space, which makes them more suitable for travel. Most in-ear models are made to have a strong seal inside the ear to isolate the listener from their environment. Like their closed back cousins, earbuds are also good candidates for active noise cancellation. Thus, many have been seen out in public wearing their favorite in-ear models oblivious to any sounds around them, this has annoyed me many times. However, transparency mode in recent in-ear models, similar to in closed back cans, have begun to change that for the better.
Even though I personally don’t like wearing earbuds much, and often bash them, In-ear headphones are the favorites of many, and some models even require a visit to an audiologist. A medical doctor, who among other medical situations dealing with the ear, in this case makes an actual mold of the inside of the person’s ear canal for an exact custom fit.
We’re all humans, and also quite different from each other, so it’s not surprising that even includes how we listen. Some people don’t even like headphones at all, but speakers are a whole different story for another day.