Telephone

Telephone is a telecommunication device that permits two or more users to conduct a conversation when they are too far apart to be heard directly. A telephone converts sound, typically and most efficiently the human voice, into electronic signals suitable for transmission via cables or other transmission media over long distances, and replays such signals simultaneously in audible form to its user.

History

The telephone was invented by Alexander Graham Bell who applied for his patent on the telephone, at the New York Patent Office, on February 14, 1876. The patent is issued on March 7, 1876, in the names of Alexander Graham Bell, Boston, Massachusetts, USA. Bell's patent 174,465, was issued to Bell on March 7, 1876, by the U.S. Patent Office. Bell's patent covered "the method of, and apparatus for, transmitting vocal or other sounds telegraphically ... by causing electrical undulations, similar in form to the vibrations of the air accompanying the said vocal or other sound."

Design

The essential elements of a telephone are a microphone (transmitter) to speak into and an earphone (receiver) which reproduces the voice in a distant location. In addition, most telephones contain a ringer which produces a sound to announce an incoming telephone call, and a dial or keypad used to enter a telephone number when initiating a call to another telephone.

Impact

The telephone has had a big impact on the world. It has made communication easier and faster. It has also made the world a smaller place as people can call each other from different parts of the world.

See also

• Mobile phone
• History of the telephone
• Invention of the telephone

References

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