The telephone earpiece on a phone is called a headset.

The usual cause is a faulty wire somewhere between the earphone itself and the phone. Try using another earphone that you know works properly. If that cures the problem - you know your original earphone needs replacing. If not, the fault is in the phone itself.

"Earphone" does not have a prefix or a suffix. It is a standalone word that combines "ear" and "phone" to describe a device for listening to audio.

its a phone you put on your ears

The iPad has a standard 3.5-mm stereo headphone jack and will work with most brands of earphones.