A recording made in 1860, 17 years before Edison invented the phonograph, has been played back for the first time, thanks to the work of a group of audio historians, recording engineers and scientists.
Made on April 9, 1860 by French inventor Édouard-Léon Scott de Martinville, using a device called a phonautograph, the recording was never really meant to be heard, but rather used as a tool to analyse sound.
But now, as part of the First Sound initiative, it's been made possible for us to hear what was stored by the device.
The recording, which can be heard by clicking here, is of a voice singing a short piece of a French folksong, Au clair de la lune, Pierrot respondit. The phonautograph made the recording by etching it with a stylus onto paper blackened by the smoke from an oil-lamp.
The operator cranked the device by hand while the recording was being made, and the result was a trace on the paper representing the sound, seen left.
Scott started his experiments six or seven years before this recording was made, but the 1860 phonautograms, or phonoautograph recordings, are thought to be his most technically accomplished.
But there was one problem with the system - it could make recordings, but there was no way of playing them back. So while the system enabled scientists to study the nature of sound - Edison himself used it to examine the noise made by the elevated railroad systems in Manhattan - it was impossible to hear the performance, or the noise being studied, again.
First Sounds historians Patrick Feaster and David Giovannoni examined phonautograms made by Edison and his associates in America, and also Scott recordings submitted as part of patent applications in 1857 and 1859, as he refined the design of the recording apparatus from the early version seen at the top of this story.
Giavannoni made high-resolution digital scans of each phonautogram, which were then converted into sound by Earl Cornell and Carl Haber, working at the Lawrence Berkeley National Laboratory in California.
They used technology designed to preserve recordings on early formats such as phonograph discs and cylinders, which scans the recording without contact, creating a digital representation playable using a virtual stylus.
The recordings underwent further restoration and adjustments to stablise their speed and remove noise.
You can hear more phonoautogram recordings, and hear the stages of the restoration process, by clicking here.