Telephones are devices for communicating sound, especially speech. Tele- means long distances and -phono means sound, voice or speech.
The telephones people use came about from a device invented by Alexander Graham Bell in 1876. Although Bell is recognised as the inventor, many others attempted to produce such a device. Image: ALEXANDER GRAHAM BELL IN 3-D By Okinawa Sobaunder a Creative Commons License Some rights reserved
Telephones are an important invention as they save people time when they need to communicate with someone in a hurry, over long distances. Mailing a letter may take two weeks to reach another person. A telephone is instant.
Telephones are made using plastic and metal. They come in many different colours such as black, silver, grey and cream. The body of the telephone contains numbered keys 0 – 9. A coiled wire protrudes from the side of the phone and is attached to the handset, which sits on the switch hooks. At one end of the handset is the receiver and at the other end is the transmitter. Both the receiver and transmitter have holes punched into the plastic.
Inside the body of the telephone is a circuit board. Wires from the circuit board are attached to the handset, switch hook, keypad and wall outlet. Wires from the wall outlet are attached to the wires in the local telecommunications system. In this way, the voice is transmitted along wires to another person who also has this equipment.
When a call has to be made, the handset is lifted from the cradle and the receiver end is placed on the caller’s ear. The transmitter is placed near the caller’s mouth. The caller enters the other person’s telephone number by pressing the numbers on the keypad. This sends an electric signal through the wires to the phone at the other end, which then rings.
Upon hearing the telephone ring, the person receiving the telephone call must pick up their handset in order to communicate with the caller.
These days are many different types of telephones, for example cordless phones and mobile phones.