Apple QuickTime movie | 2003-04-17 | 9.2 MB | 256x192 | 15fps | 2 minutes, 17 seconds
Transcription: A telephone handset contains a transmitter and a receiver. When a person speaks into the mouthpiece, the transmitter produces a varying electric current that fluctuates according to the pattern of the sound waves. When the signal reaches its destination, the telephone's receiver converts the electric signal back into sound waves, and the listener hears a duplicate of the speaker's voice. Telephone signals can travel almost instantly around the world through a vast network that includes computers, cables, radio receivers and transmitters, and satellites. Most telephones connect with the network ...
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