On-ear Headphones, as the name suggests are fashioned to go into the ears and are therefore perfect for those who enjoy their music in the most comfortable listening experience possible. They do not block out any external noises, and the result is a truly immersive audio experience. If you're looking for a great pair of headphones that will offer you the best audio performance, then these may be the ideal choice for you.
These types of headphones work best when they are worn around the head. If you wear them whilst doing other things, such as reading or watching TV, they will likely block out any external noise and so will offer you a true audiophile experience. Of course, as with any type of headphones, they are subject to feedback, which means that you will need to give them a good quality of sound. You should test them by listening to plenty of music with them out of a CD and judge for yourself if they pick up the sounds well. Don't worry too much about this, because even though the first few songs may be distorted, your ears will become accustomed to the distortion and will soon notice that the songs no longer sound as distorted.
On-ear Headphones are also very closely related to open earphones, which are headphones that open up to the ears and then seal them back, enclosing the ears in an acoustic cage. They are perfect for blocking out background noise and make for an excellent listening experience, but they can make the person wearing them feel uncomfortable due to the fact that they are not completely sealed in. However, they have a tendency to produce the loudest sound of all the types of headphones. Their main advantage is that they do not block out any external noise, which is a big bonus if you are on a call, because blocking out background noise is a huge advantage when on the phone.
There are many styles of on-ear headphones, as well as brands. Fostex is one company that is well-known for their headphones. Most are about the size of a normal earring, so they won't interfere with your glasses or earrings at all. The driver comes into contact with a thin wafer of plastic that encases the driver inside the ear cup, which is usually made of a hard material. The driver is enclosed within this and provides the source of the audio as well as the audio from the speakers.
There are many other styles of on-ear headphones as well. One style is the "over the ear" headphones, where the driver fits into the ear cup, much like an ear bud. These kinds of headphones work by using tiny microphones to capture the sounds around your head. Then these are amplified through the driver and sent to the headphones. They are great if you want to listen to music while doing something else - they are often used in exercise classes because they can be worn without blocking out the ambient sounds around you.
Another type of on-ear headphones are the "sub-ear" headphones. Just like the over the ear headphones, the sub-ear headphones use tiny microphones to capture the sounds around your ears. But unlike the over the ear headphones, these do not fit into your ear bud but instead rest against your ear.
The third type of on-ear headphone is the full-range over the ear headphones. These are usually created using transducers, instead of tiny drivers. This way they can capture noise in any direction, and spread it around. This is great for people who travel a lot, since they do not need to make sure that the sound they hear isn't being blocked out by other sounds.
So, which one is the right one for you? It depends a lot on what you need it for. If you just want to listen to your music while driving, then a good choice would be the simple ear buds. If you need to wear the headphones while doing something more active, then the full-range would be your best bet. Just be sure to check your ear bud's compatibility with your device.