How to restore retro sound? The work of audio archaeologists from Southampton


    A damaged wax cylinder, the sound recording of which has been restored using modern technologies.

    There are quite a few archaic devices in the world for recording sound. There are also audio recordings made by such devices. By “archaic” is meant recording devices that record sound on wax cylinders and records. Such devices were relatively widespread in the late 19th - early 20th century.

    So, the records made by these devices are fragile, and time has made wax cylinders completely unreadable relics. Such a cylinder would simply collapse before being able to use a traditional pickup. But since the issue of restoring the oldest audio recordings is relevant, the problem is still solved. Such a solution was the use of an optical scanner.

    The surface of the cylinder is carefully scanned, and the data obtained is processed in specially written software. Then a virtual pickup is used, based on the operation of the algorithms for converting the image into sound.

    Back in Habré, they previously wrote that it was in this way that Graham Bell's voice was restored from a recording made back in 1885. Then it was possible to reproduce the sound recorded on tin foil in Edison's laboratory in 1878. But the earliest record that could be restored is the sound recorded in 1860 by the Frenchman Edouard-Leon Scott de Martiville. The inventor recorded the sound on a sooty paper sheet, and not on wax, which complicated the task of restoring sound, but still did not make it unsolvable.

    How to restore sound?

    The most advanced technology for reconstructing sound from various types of surfaces was developed by specialists at the University of Southampton .

    At the very beginning of the work, experts tested three types of sound recovery technologies:

    Polychrome



    Laser triangulation



    Confocal laser



    After a series of discussions, experts came to the conclusion that it is best to use the first method that allows you to restore sound most fully. Here, not only the depth of the track is recorded, but also its shape.

    According to the results of the study, such an apparatus was built:



    The cylinder is placed on the rotor, a lens and a scanner are located on the side to capture reflected rays. All this is passed through a spectrometer, and fed to a computer for analysis.



    After processing, the sound is already suitable for listening.







    Thus, the proposed method of sound restoration does not imply the use of any mechanical methods of influencing the wax cylinder (or any other similar carrier). The goal of the project is to restore all retrospective records that are important for science or art, no matter how safe they are.

    The resulting sound in some cases is processed by special software to reduce noise and highlight the soundtrack.

    Examples of recovered materials can be heard by clicking on the links:

    “Beautiful Birds Sing On” , 1905 (9022: Edison Gold Moulded Record)

    “Lonesome” , 1909

    “My Wild Irish Rose” , 1910

    By the way, for comparison, you can listen to the recording restored by the invasive method using a conventional pickup (software noise reduction is used), and the same recording restored using the optical non-invasive method.

    Conventional software noise reduction method

    Same audio track restored using optical method

    By the way, there is an opinion that on some surfaces there is a “dead sound”, a kind of paths created, for example, by a builder applying plaster. If the builder sang or talked while working, his trowel vibrated, and these vibrations are reflected on the plaster itself. And if this kind of track is somehow restored, we can hear the voices of people who lived many hundreds of years ago. Of course, this is from the field of science fiction (and this idea was presented by a science fiction writer), but the idea is interesting, although it can hardly be used in practice ...

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