Earphones are an evolved form of headphones that was first invented by Nathaniel Baldwin in his kitchen and was supplied to the US Navy. Nathaniel Baldwin was born on December 1, 1878 in Millard County, Utah. Even when he was a child, he had a technical bend of mind and he went on to pursue a degree in electrical engineering from Stanford University. Nathaniel then worked at hydroelectric plants and was always interested in sound amplification. This interest of his ultimately led him to develop the modern head phone in 1910.
Ear phones are a type of head phones that are small in size and have two small loud speakers which can be placed just outside the ear canal. They are connected by conducting wires to an audio source like CD player or a radio. Ear phones can be used with fixed sets such as radio, DVD players and computers and also with portable devices such as mobile phones, walkmans and mp3 players.
Today cordless ear phones are also available in the market and they do not have a wire connecting them to the device. Such ear phones receive the radio signals or infrared signals through various transmission links such as FM, Wi-Fi, and Bluetooth. Ear phones ensure privacy in listening and they are portable and inexpensive when compared to the other types of head phones. They also provide sound fidelity of high level compared to a loud speaker of same cost. However one drawback with earphones is that the continuous exposure to high volume increases the risk of hearing loss.