An earpiece is a part of an instrument that is placed on or in the ear. Technically, all phones are also earpieces, as the term is very broadly defined. For example, the part of the telephone that you hold up to your ear is an earpiece. Doctor's stethoscopes also include earpieces and specialist earpieces are also commonly used with two-way radio equipment. These are all different devices, but they share the same name. The term is also used to describe the two 'arms' that keep a pair of glasses attached to the wearer.
For our purposes, however, we'll be talking about mobile phone earpieces, the kind that allow a wearer to operate their phone on a 'hands free' basis (eg when driving). Such devices are commonly known as 'Bluetooth Headsets' because they use Bluetooth technology, (itself named for Harold Bluetooth, who was born in about 935 and was king of both Denmark and Norway before his death in 985 – but that's just trivia, you don 't need to know that!).
Essentially, an earpiece turns electronic signals into sound waves and then directs those same sound waves into the ear. This allows you to hear the person on the other end of the phone. There are many different styles of mobile phone earpiece, but there are only two major types.
Radio earpieces are organized broadly into two different types – wired accessories and cordless or wireless accessories. The wireless variants use either RF waves or infrared signals to attach to the signal sources. Headphones for CD players, pcs or cell phones are some examples. A signal transmission link is used, like Bluetooth® or Wi-Fi. The wired earpiece is physically attached to the signal source. To facilitate this, connectors near the end of each of the cords are inserted into the signal source. Jack sizes were standardized, and the most typical size is a 3.5-mm (about 0.2 inches) that was introduced into the marketplace by Sony in 1979. The much older, 1/4 inch (about 6.4 mm) jack is used only in professional gear
A Bluetooth headset allows your mobile phone to be securely stored away in your pocket, leaving your hands free to perform any task you see fit. Typically, the audio quality is poor and only works over very short distances, but it is acceptable for speaking and listening, conversations between friends, conference calls and so on.
Bluetooth headsets are popular because they allow a busy person easy access to a phone, without having to fumble around in their pockets or put things down. They are a convenience first and foremost, but they can be very useful for drivers, commuters and businesspeople on the go.