Telephone conversation?

Question

When I call someone through phone, I speak the voice is changed into electrical signals, How?

The person at receiving end listens the exact words, even though during transmission it was just like electrical signal through conductor.

How it extracts the wordings from the electrical signals, If I connect it with any other electrical signal (such as wiring ) will it do the same?

Answer 1

Holy crap, can anyone here answer a question without a cut and paste job from wikipedia?

Very basic explanation here. A detailed one would take forever.

Think of it this way, when you talk, sound waves are leaving your mouth. The sound wave is analyzed and broken into an electrical signal by its frequency and transferred to the far end. There it is re-assembled with the exact frequency and is transmitted to the actual telephone that you called. Reference "Time division multiplexing" and you can get a really interesting study piece.

Answer 2

"The telephone operates on simple principles. A telephone mouthpiece contains a thin metallic coating separated from an electrode by a thin barrier (today we use plastic) which connects to a wire carrying an electric current. When a person speaks into the mouthpiece, the acoustic vibrations from her speech push the metallic coating slightly closer to the electrode, resulting in variations in voltage and therefore a speedy conversion from acoustic to electric energy. The electric pulses are conveyed through a wire to the speaker on the other end, where electric pulses are converted into acoustic energy again.

Converting speech to electrical energy before transmission is far more efficient than conveying speech through a mechanical channel, for example a metal pipe, because the walls of mechanical channels absorb so much of the acoustic energy as it travels. Well-insulated wires, however, are effective at protecting electrical energy from dispersing before reaching its destination. Electrical pulses travel at the speed of light, whereas acoustic pulses are limited by the speed of sound."

http://www.wisegeek.com/how-does-a-telephone-work.htm

Answer 3

In the fields of communications, signal processing, and in electrical engineering more generally, a signal is any time-varying quantity. Signals are often scalar-valued functions of time (waveforms), but may be vector valued and may be functions of any other relevant independent variable.