Audio historian David Giovannoni recently unearthed a 10-second clip of a woman singing the folk song "Au Clair de la Lune" from 1857. The recording predates Thomas Edison's "Mary had a little lamb" (which was previously credited as the oldest recorded voice) by 17 years. The song was captured using a phonautograph, a device using a needle to etch sound into paper, created by inventor Edouard-Leon Scott de Martinville that created visual recordings of sound waves.
de Martinville, a Parisian bookseller, librarian, typesetter and tinkerer, died in 1879, convinced that Edison was wrongly credited with his milestone. Unlike Edison's phonograph, the phonoautograph was unable to playback recordings.
From yesterday's New York Times.