A 1860 voice recording, hidden for 150 years, was finally heard in 2008, revealing the oldest known human voice. It was made by a French inventor's early sound-tracing device.
1860 voice recording discovered
On April 9, 1860, in Paris, Édouard-Léon Scott de Martinville likely sang "Au clair de la lune" in front of an early sound-recording device. This event predates Thomas Edison’s phonograph by 17 years, but the recording remained unheard until 2008.The recording’s long silence
Scott’s device, called a phonautograph, traced sound onto a sheet of paper coated with soot. The paper survived and was stored at the Académie des sciences in 1861. However, the device could not play back the sound, leaving the recording in silence for nearly 150 years.Earliest known human voice
The 1860 recording is currently recognized as the oldest known human voice, though earlier sound traces from 1853–1854 exist. These earlier recordings, however, are not audible. The phonautograph was patented in 1857, and the 1860 recording is the only one that has been successfully decoded.Scott’s background and invention
Édouard-Léon Scott de Martinville was a Parisian typesetter. He patented the phonautograph in 1857 as a tool for studying acoustics. The device captured sound waves by scratching them onto a soot-covered sheet. The first tests in 1853–1854 were inaudible, and Scott later used a tuning fork to help refine the process.The problem of the crank
The phonautograph used a hand-cranked cylinder, which made the recording speed inconsistent. This caused the sound to become unrecognizable. To solve this, Scott marked the sheet with a 250 Hz tuning fork. This allowed researchers to correct for the uneven speed and recover the sound.Decoding the recording
In 2007 and 2008, researchers scanned the sheet at the Académie des sciences and the INPI archives. The images were sent to California, where scientists used a "virtual stylus" to convert the soot traces into sound. The first playback was released in March 2008, revealing a 10-second excerpt believed to be a man’s voice.Refining the recording
In 2009, researchers corrected the playback speed, extending the recording to about 20 seconds. The lyrics were also revised in 2010 to match the correct version of the song. The recording shows Scott may have paused the device, possibly to check the sheet’s space.Multiple recordings and legacy
Scott recorded "Au clair de la lune" at least three times in 1860. One version is preserved in the Institut de France library. In 2015, UNESCO added Scott’s phonautograms to its Memory of the World register, recognizing their historical significance. The collection includes 50 recordings across four French institutions.
