New Hope For Old Sounds

The oldest verified surviving recording is an 1878 tin cylinder of a talking clock (you can hear it at tinfoil.com/cm-0101.htm). There's just one problem, however; the recording's surface noise is so pronounced that you can barely hear the featured attraction. Chalk it up to age, imperfect recording media, poor storage, or even to the ravages of mold, but the facts remain the same—we're in danger of losing our audio patrimony: the hundreds of thousands of historical recordings from the dawn of recording.

The Library of Congress takes this impending crisis seriously enough to have entered into an interagency agreement with the Lawrence Berkeley National Laboratory (LBNL) in Berkeley, CA to reconstruct mechanical recordings using technologies derived from particle physics research. Vitaliy Fadeyev and Carl Haber have been part of an international search for a hypothetical subatomic particle called the Higgs boson, named after Peter Higgs, who theorized that such particles or sets of particles are responsible for endowing objects with mass. The Swiss-based international particle physics laboratory CERN is searching for the Higgs boson in the detritus of particles smashed in its new particle accelerator, the Large Hadron Collider (LHC), and Fadeyev and Haber have been using an extremely high-resolution microscope called an OGP SmartScope to examine silicon wafers as part of the project.

Technically, the OGP SmartScope isn't a microscope, but a four-axis measuring machine. Translation: it uses a digital camera to capture highly magnified images and then its computer employs "the latest vertical Z-axis algorithms" to analyze and map the shapes and locations of the objects under examination. The SmartScope is capable of resolution of up to 0.25 microns.

Fadeyev and Haber have been using the LBNL's SmartScope to map the grooves of early recordings, at which point they utilize a computer program to read the groove data and convert it to digital music files. The system, called audio metrology, is non-invasive and does no damage to the delicate (and sometimes decaying) surfaces of the original recordings. And, as Haber told The San Francisco Chronicle, the software can be "programmed to recognize dirt, scratches, and debris and delete them from the image, similar to retouching a photograph."

Does it work? Judge for yourself. At the LBNL's Sound Reproduction R&D Home Page, the laboratory has posted audio files of several recordings as played with a stylus, reproduced utilizing audio metrology, and as reproduced on commercially released CDs with conventional noise reduction. The same page also provides a link to a downloadable .pdf file of Fadeyev's and Haber's JAES paper, "Reconstruction of Mechanically Recorded Sound by Image Processing."

"The preservation of the audiovisual record is the preservation of the language of the 20th century," said Mark Roosa, director for preservation at the Library of Congress. "The more and more we talk about the possibilities [of audio metrology], the more and more we're excited."

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