Au clair de la lune recording

In 1860, French inventor Édouard-Léon Scott de Martinville made the earliest known sound recording, capturing himself singing the French folk song "Au clair de la lune." This recording went largely unnoticed and was overshadowed by Thomas Edison's phonograph, which famously recorded "Mary Had a Little Lamb." However, in March 2008, researchers rediscovered Scott de Martinville's recording and sent it to the Lawrence Berkeley National Laboratory, where they used a computer program to convert it into audible sound.

Overview
Sound engineers at the Lawrence Berkeley National Laboratory initially played the phonautograms received from First Sounds in March 2008 at a speed that resulted in a 10-second snippet, which seemed to feature a woman or child singing or humming a tune. Later, researchers discovered that a misinterpretation of a reference frequency had led to the playback speed being doubled. Once corrected, it became apparent that the recording was likely of a man, probably the inventor Édouard-Léon Scott de Martinville himself, singing the French folk song "Au clair de la lune" at a slow pace.

1853 or 1854-1860
In 1853 or 1854, French inventor Édouard-Léon Scott de Martinville conceived the idea of creating a sound reproduction system after studying a diagram of the human ear. Inspired by this, he began developing what he termed "le problème de la parole s’écrivant elle-même" ("the problem of speech writing itself"), aiming to replicate the ear's capacity to capture and reproduce sound.

On 25 March 1857, Scott de Martinville patented his device, which he called the "phonautograph."

By 1857, with support from the Société d’encouragement pour l’industrie nationale, the phonautograph had advanced to a point where it could record sounds with sufficient accuracy. This development led to its adoption by the scientific community for various studies and experiments.

On 9 April 1860, Scott de Martinville recorded himself singing the French folk song "Au clair de la lune" ("By the Light of the Moon") using his invention, the phonautograph. Unlike later devices, Scott de Martinville's phonautograph was not designed to replay recordings. Instead, it captured sound waves visually on paper, allowing for the visualization of sound vibrations, which he called phonautograms.

2008
Before March 2008, it was widely believed that Thomas Edison's phonograph was the first sound reproduction system. However, in March 2008, phonautograms created by Édouard-Léon Scott de Martinville were discovered and revived by First Sounds, an informal collaborative of American audio historians, recording engineers, and sound archivists. The phonautograms were subsequently sent to Lawrence Berkeley National Laboratory, where the sound waves and vibrations were converted into audible sounds. This process achieved what Scott de Martinville had not incorporated into his original invention.

Sound engineers initially played the phonautograms at a speed that resulted in a 10-second snippet, which seemed to feature a woman or child singing or humming a tune. Later, researchers discovered that a misinterpretation of a reference frequency had led to the playback speed being doubled. Once corrected, it became apparent that the recording was likely of a man, probably of the inventor Édouard-Léon Scott de Martinville himself, singing the French folk song "Au clair de la lune" at a slow pace.