Most people tend to believe that Thomas Edison is the first person to record sound and play it back using a phonograph. However, that notion is only partly true. Though Edison was the first person in history to play an audio file, he was not the first to record sound. To clarify the confusion, the first-ever recording of a human voice was made using a phonautograph. Invented by French bookseller and printer, Édouard-Léon Scott de Martinville, the phonautograph could only record sound but not play it back. The recordings were made in 1860 but were soon forgotten. However, in 2008, modern technology was used to playback the recording for the first time.

The phonautograph, patented in 1857, is the first known technology capable of recording sound. The device could transcribe sound waves but not play it back.

A precursor to Thomas Edison’s phonograph, the phonautograph was invented by Édouard-Léon Scott de Martinville and patented on 25th March 1857. The technology was capable of transcribing sound waves as deviations and undulations. The captured data would then appear as a line on smoke-blackened glass or paper. It was originally designed as a laboratory instrument that could be used for studying acoustics.

The data produced through a phonautograph could help to visually measure and study the waveforms and amplitude envelopes of speech as well as other sounds. It could also be used for comparing the frequency of two simultaneously recorded musical pitches. However, compared to modern recording technology, the phonautograph produced an insubstantial tracing of a two-dimensional line. That is why it could not be played back.

Scott’s invention of the phonautograph was inspired by the daguerreotype and the anatomy of the human ear.

A bookseller and printer by trade, Édouard-Léon Scott de Martinville was neither a professional inventor nor a scientist. However, he was fascinated by the field of science and wanted to secure his position in it. He got the idea for the phonautograph sometime between 1853 and 1854. While studying the daguerreotype, the first commercially successful and publicly available photography technology, he asked himself that if a camera can replicate the eye to create an image on paper, could a mechanical ear produce sound on paper?

His understanding of human anatomy also came into play when inventing the phonautograph. The device was analogous to the human ear and had parts that resembled the ear canal, ossicles, and eardrums. After experimenting with several versions, Scott finally settled on a design that had a funnel-shaped horn or an open-ended barrel to mimic the ear canal. At the small end of the horn or barrel, he attached a flexible parchment to simulate the functions of the eardrum. A lightweight stylus, originally a pig bristle, was attached to the membrane. The stylus would be connected via an indirect linkage, which would serve as the ossicles.

A moving surface of glass or paper was coated with lampblack which is carbon deposited on a surface. The design allowed the simulated ear to pick up sound and transmit it to the bristle which would then trace a line on the lampblack surface. The line would also modulate according to the changes in air pressure. This would create a graphic representation of the sound waves much like a seismograph picks up earthquakes.

French poet and inventor Charles Cros was the first to realize that recordings made on a phonautograph could be turned into sound. However, before he could work on it, Thomas Edison announced the phonograph.

When Édouard-Léon Scott de Martinville used the phonautograph to record himself singing the French folk song “Au Clair de la Lune,” he did not plan for it to be played back and heard as audio. In fact, before the late 1870s, no one had even considered the idea that the transcribed recordings contained enough information that could be used for recreating the sound. In April of 1877, French inventor and poet Charles Cros theorized that the phonautograph recordings could be converted into sound using photoengraving.

The idea was that the tracing would be photoengraved on a metal surface for creating a playable groove. Then a diaphragm and stylus would be used for reversing the recording process and recreating the sound. However, before this theory could be put into practice, Thomas Edison announced his invention, the phonograph, which was more advanced technology. The phonograph indented sound waves into a tinfoil sheet, which is why the recording could be played back almost immediately.

The phonautograph recordings were finally turned into audio in 2008, almost 150 years after they were first recorded.

When the phonautograph failed to make a profit, Édouard-Léon Scott de Martinville went back to selling books. The device and some of the recordings were sent to a museum. Over time, the recordings became more and more obscure, and no one thought to create playable versions of them. However in 2008, American audio historians found a few promising specimens of phonautograms while going through Scott de Martinville’s papers at the French patent office.

They turned over their findings over to the Lawrence Berkeley National Laboratory and used a software program called “IRENE.” The program specialized in extracting sound from the wax cylinders without ever needing to touch the delicate surface. Using the software, the team was able to produce high-quality images of the recording. Then, thanks to modern image processing capabilities, the recording was played back as audio for the very first time.

At first, it sounded like a child or young woman was singing the folk song “Au Clair de la lune.” However, after modifying the audio, they realized that it was a man (possibly the inventor himself) singing. To bring the audio to life, they used various techniques such as noise reduction, quantizing, and tuning. They also stretched the recording to a more natural timing, cleaned up the harmonics, and added a stereo effect and reverb to digitally enhance the audio.

This way, the unrecognizable ghostly sound was turned into an almost pleasing tune. Thanks to the efforts of the team, a whole new dimension was added to this long-forgotten invention of Édouard-Léon Scott de Martinville.

[Sources: 1, 2, 3, 4]