解析库 > Kaplan
The phonograph cylinder was a remarkable invention that allowed sounds to be recorded and reproduced--the earliest instrument to do both (édouard--Léon Scott de Martinville created a phonautograph that could record sound in a visible format, but could not play it back). First invented by Thomas Edison in 1877, the phonograph cylinder was wrapped in a scratchable medium and then rotated under a stylus that was attached to the speaking tube. When sound entered the tube, the attached diaphragm would vibrate, causing the point of the stylus to create indentations of varying depths; meanwhile, the cylinder was rotated by a hand crank at a rate of 60 revolutions per minute. The cylinder could then be played back by drawing a lighter stylus along the indentations that caused the diaphragm of a second tube, the speaking tube, to vibrate, replicating the recorded sounds. Over time, the phonograph slowly evolved. Cylinders were wrapped in wax instead of with tin foil, a motorized crank and more effective recording media were developed, and the cylinder itself was replaced with a disc that allowed for more durable creations. These evolved into record players as we know them.