As Thomas Edison was experimenting with the telephone in 1877, he happened to place his hand on the back of the microphone while he was speaking into it. As he spoke into the device, the vibrations of his voice caused a metal piece to vibrate and prick his finger.
If the sound of his voice could hurt his finger, Edison thought, maybe it could do some practical work as well. Perhaps, he thought, a vibrating needle could make a groove in tin foil wrapped around a cylinder, then by rubbing the needle back over the groove, perhaps it would recreate the same sound.
When his skeptical engineer, John Kruesi, brought the just-completed device to him, Edison wrapped the cylinder in tin foil, turned the crank and sang "Mary had a Little Lamb" into the speaker. Then he played it back and the men crowding around the device heard Edison's voice faintly singing the children's song.
Then the astonished Kruesi spoke German into the device and turned the crank to play back the sound. Sure enough, Edison's phonograph spoke German as well!
Thomas Edison invented the phonograph. Originally it pressed a needle on a metal cylinder wrapped with tin foil.
In 1885, U.S. scientists Chichester Bell and Charles Tainter improved on Edison's invention, by making their recordings on wax-covered cardboard cylinders. In 1887, Emile Berliner, a German immigrant to the United States, invented the gramophone, which used the same principle, but played from a shellac disk instead of from cylinders.
But the most revolutionary change in sound recording didn't come until about 1978 with the advent of digital recording.
Until that time all recordings, both records and tapes, were analog. This means they have the same kind of wiggles in them that Thomas Edison's first recording had, though in the case of tape recording these "wiggles" are magnetic.
But records and tapes have problems. They wear out, for one, and there is always unwanted surface noise and sound distortion.
With compact disc recordings, however, these problems disappear.
On compact disks, the music is recorded mathematically and when it is replayed, it has much greater fidelity to the original sound.
