https://online2.tingclass.net/lesson/shi0529/0009/9526/U01_6FLT2.mp3
https://image.tingclass.net/statics/js/2012
So you think downloading music from the Internet through a phone line is a really cool modern thing? Not so. In 1896, Thaddeus Cahill Filed a patent on the instrument for transmitting music electronically, and until 1914 he sent music signals down telephone lines with this instrument. And he wasn’t even the first. Elisha Gray transmitted music over a telephone line in 1876, which was the same year the telephone was invented. Gray invented the first electronic music instrument in 1874, calling it the “Musical Telegraph”. Alexander Graham Bell also designed an experimental “Electric Harp” for speech to be transmitted over a telephone line using technology similar to Gray’s. Bell was a speech teacher for the deaf. In 1879 he created an instrument to measure hearing loss. That is why the degrees of loudness came to be measured in bels ordecibels.
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