Berkeley, CA (May 4, 2004)–Through an interagency agreement with the Library of Congress, the same technology used to study subatomic particles is helping to restore and preserve the sounds of yesteryear.
“We developed a way to image the grooves in a recording that is similar to measuring tracks in a particle detector,” said Carl Haber, a senior scientist in Lawrence Berkeley National Laboratory’s Physics Division who developed the technology along with fellow scientist Vitaliy Fadeyev.
Their work could ultimately enable the Library of Congress to digitize the thousands of blues, classical, Dixie, jazz, and spoken word recordings in its archives. The mass digitization of these aging discs and cylinders will both preserve the nation’s musical history and make it accessible to a wide audience.
The collaboration takes advantage of Berkeley Lab’s decades of experience analyzing data generated by high-energy physics experiments. “We thought these methods, which demand pattern recognition and noise suppression, could also analyze the grooved shapes in mechanical recordings,” said Haber.
To test their hunch, Fadeyev and Haber turned to a precision optical metrology system used by Berkeley Lab physicists. They programmed the system to map the undulating grooves etched in shellac phonograph discs. The images were then processed to remove scratches and blemishes, and modeled to determine how a stylus courses through the undulations. Lastly, the stylus motion was converted to a digital sound format.
The result is a digital reproduction of a mechanical recording, with each wiggle, bump and ridge in the recording’s grooves faithfully captured, and each scratch ironed out. Although still under development, the technology could eventually give the Library’s staff a better method to restore some of the 500,000 items it provides preservation treatments to each year, from a collection of nearly 128 million items in all formats.