On April 9th, 1860, French inventor Edouard-Leon Scott de Martinville created the earliest known recording of a recognizable human voice. Predating Thomas Edison's phonograph by 17 years, Martinville used his invention, the phonautograph to record a ten-second fragment of the French folk song "Au Clair de la Lune" by channeling sound through a horn to a needle that etched waveforms onto a sheet of paper blackened by oil lamp smoke. He never intended the phonautograph to be used for audio playback, believing that humans would eventually learn to read the visual squiggles it made like text. Because of this, the recording stayed silent for nearly 150 years until 2008, when a team of American audio historians from the First Sounds project used digital scanning and a "virtual stylus" to convert the soot-covered lines back into audible sound. The voice was initially mistaken to be a little girl due to the playback speed error, but it was further investigated and revealed to be Martinville himself.
