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May-June 2007
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Keeping the VibesHow do you play a broken record? “Take a picture of it,” says audio engineer David Ackerman, who heads the Audio Preservation Services (APS) unit in the Loeb Music Library. Ackerman explains that new technology (developed for IRENE—the Image, Reconstruct, Erase, Noise, Etc. project of the Library of Congress, based at the Lawrence Berkeley National Laboratory at the University of California, Berkeley) can optically scan a record groove. Then, with high-resolution digital maps of the shapes of the grooves, computers build digital files that reproduce the audio data on the original record, in many cases rescuing sounds from the realm of seemingly permanent silence. Ackerman monitors such emerging technologies, which might someday come to Harvard, as part of his mission within the Harvard College Library—preserving rare, even unique, audio materials and making them accessible. His little-known group of four audio engineers quietly does for sound recordings what art conservationists do for paintings: preserve, clean, repair, restore, and ensure that they live on. But sound preservation involves computer data files, because the work nearly always means transforming an analog recording into a digital one. Although none of Thomas Alva Edison’s wax cylinders has yet presented itself, the analog materials do come in widely diverse formats, including disk records that are made of aluminum, shellac, acetate, and vinyl; reel-to-reel tapes in both acetate and polyester-based formulas; cassette tapes, digital audiotapes, Dictaphone databelts, minidiscs, and even eight-track cassettes. (The music library does own a couple of boxes of wax cylinders, but APS does not own a wax-cylinder player.) The output formats are varied, too. The engineers can burn CDs and CD-ROMs, as well as audio and video DVDs. They can make analog tapes and create files in three Internet-friendly modes: Real Audio, MP3, and MP4. (The last two are playable on iPod devices; the music library keeps several, so patrons can borrow one, go into a listening room, and work directly with MP4 files that APS has reformatted and placed on a library server.) Recordings show up in a range of conditions. “The Harvard College Library has enormous holdings of audio and visual material,” says Ackerman. “It is scattered throughout many units and has been cared for differently in different places. Storage conditions vary widely, from good to very bad. We’ve seen tapes that were stored in a hot, humid attic. Some recordings are unplayable.” Take certain audiotapes manufactured during a particular period in the late 1970s and early 1980s that tend to suffer from “sticky shed syndrome.” With age, the tape’s backing gets sticky and starts to peel off, shedding the ferric oxide on the recording side of the tape, where the magnetic signal resides. “You can do things like ‘baking’ those tapes in a laboratory convection oven,” Ackerman says. “If done properly, you may be able to recover all or some of the magnetic signal.”
“Sticky shed syndrome” causes inadvertent loss of data, but deliberate loss of data, as in the compressed-file formats used to save memory space, can pose even more vexing problems. “Compressed file formats are a nightmare for us,” says Ackerman. “It’s about throwing the data away.” He explains that closed proprietary file formats like those used by Apple’s iTunes build in copy protection—which, of course, makes copying and preserving the file difficult. “Studios have a vested interest in seeing those things go out of print and become unavailable,” says Ackerman. “Then demand for them can build again. But suppose, say, they are bought out by a company that decides to blow off preservation activities. Twenty years out, that could also blow off a chunk of our cultural heritage. The next generation, which might only have heard compressed, auditorily diminished recordings, wouldn’t have a benchmark of how some song originally sounded, and might even ask, ‘Why are we spending this money to preserve?’ ” 1 | 2 | continued >  
 
 
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