Ear

Headphones are pairs of tiny loudspeakers. Sometimes, they may comprise only a single speaker that can be attached or held close to the user’s ear. Earphones are a specific type of headphones that are small in size and placed directly outside the ear canal. Earphones do not fully envelope the ear; as such, they are not that capable of providing total isolation. They can be connected to both stereophonic as well as monophonic audio sources. Earphones can be used with fixed non-portable audio equipment like CD and DVD players, home theater systems, personal computers, etc. They can also be used with portable devices like digital audio players, mp3 player, mobile phone, etc.

Most earphones connect to the audio source using wires; however, some earphones do not come with wires and communicate with the base audio unit (personal computers, mobile phones, mp3 players, etc.) by means of encoded radio or infrared signals using Wi-Fi, Bluetooth, analogue FM, etc. Almost all wired earphones manufactured today use the 3.5 mm stereo connector, which was introduced by Sony in 1979 for use with its Walkman portable stereo tape player. Earphones are popular largely due to their low costs, portability and convenience. Since the late 1990s, earphones have gained immense popularity, as they have become the most common types of headphones, and are bundled with almost all kinds of personal music players.