from bbc: An "ethereal" 10 second clip of a woman singing a French folk song has been played for the first time in 150 years. The recording of "Au Clair de la Lune", recorded in 1860, is thought to be the oldest known recorded human voice... The new "phonautograph", created by etching soot-covered paper, has now been played by US scientists using a "virtual stylus" to read the lines. "When I first heard the recording as you hear it ... it was magical, so ethereal," audio historian David Giovannoni, who found the recording, told AP. "The fact is it's recorded in smoke. The voice is coming out from behind this screen of aural smoke."
download the phonautograph recording from 1860 of 'au clair de la lune' (130kb MP3)