Édouard-Léon Scott De Martinville – Au Clair De La Lune

This is the earliest intelligible recording of the human voice: a historic 20-second version of a French folk song "Au clair de la lune" made on April 9, 1860, 17 years before Thomas Edison invented the phonograph.

Scott de Martinville patented his own invention (n°31470) under the name "phonautographie" on March 25, 1857. A document called "Principes de Phonautographie", comprising the scientific principles of the phonautograph, was sent under sealed letter to Académie des Sciences on January 26, 1857 as an evidence of the invention.

Conceived as a stenographic device, the phonautograph recorded sound through a horn that focused the sound waves onto a membrane to which a wild boar's bristle was attached, causing the bristle to move and enabling it to inscribe the sound onto a lamp-blackened glass plate, later replaced by a lamp-blackened paper mounted on a drum or cylinder.

This device was not meant to, and could not play back recorded sound. It simply traced a visual representation of the sound waves that hit the bristle. It was not until 2008 that researchers were able to re-create the sound waves that would have been used to trace the pattern in the soot. It is presumed that the voice on the recording is that of its creator.