我国战国时代的韩国,有一个女子歌唱得很好,人们听过她唱歌,会觉得“余音绕梁,三日不绝”。其实,再好听的声音也稍纵即逝,说它“三日不绝”,只不过是人们夸张的描写。期望把美好的声音留住,一直是人们的梦想。到了19世纪下半叶,这个梦想实现了。1877年,美国发明家爱迪生发明了能把声音留住并再现出来的机器,人们把它叫做留声机。声音是一种震动。爱迪生的机器很简单(图1),一个裹着锡箔的圆筒绕 In the Republic of Korea during the Warring Misties times, a woman sang very well and when she heard her sing, she would think that “the reverberations go round and the three days are endless.” In fact, the sounds of good times are also fleeting, saying that it is “an endless stream of three days,” but an exaggeration of people’s description. It is always the dream of people to expect to keep beautiful voices. By the second half of the 19th century, this dream came true. In 1877, Edison, the American inventor, invented a machine that could hold and reproduce sound, which people call the gramophone. The sound is a vibration. Edison’s machine is very simple (Figure 1), wrapped around a tin foil cylinder