The recordings in the museum’s collection are in fragile condition due to their age and experimental nature. Until now, the technology to listen to the recordings without damaging the discs and cylinders was not available. The noninvasive optical technique used in this project to scan and recover sounds was first studied by Berkeley Lab in 2002–2004 and installed at the Library of Congress in 2006 and 2009. The process creates a high-resolution digital map of the disc or cylinder. This map is then processed to remove evidence of wear or damage (e.g., scratches and skips). Finally, software calculates the motion of a stylus moving through the disc or cylinder’s grooves, reproducing the audio content and producing a standard digital sound file.
The new preservation laboratory at the Library of Congress has hundreds of early recordings, including 200 from Volta Laboratory, to work on, and four of them are digitized for you to listen to at the Berkeley Lab website. Link -via reddit