New Technology Reveals 130-Year Old Recordings

Thanks to new digital technology, several Smithsonian Museum recordings, including those of Alexander Graham Bell dating back 130 years, have been recovered.

Using high-resolution digital scans, scientists from the Library of Congress and Lawrence Berkeley National Laboratory have been able to restore sound to six experimental disks made between 1881 and 1885 by Volta Laboratory Associates, which included Alexander Graham Bell, his cousin and collaborator Chichester Bell, and fellow inventor Charles Sumner Tainter.

Previous attempts were made to play back the recordings, such as photographically reproducing them, but scientists were unable to get sound, according to National Museum of American History Curator Carlene Stephens. Additionally, there was a risk of damaging the disks and cylinders.

The new, non-invasive optical technique used in the project creates a high-resolution digital map of the disk or cylinder. This map is then processed to remove evidence of wear or damage, such as scratches and skips. The software then calculates the motion of a stylus moving through the disk or cylinder’s grooves, reproducing the audio content and producing a standard digital sound file.

"For four of the six recordings in the feasibility study we can pretty much hear everything," Stephens says. "Two of them are hard to decipher. It's almost like a very indistinct phone answering machine recording."

Recovering sound from the six Volta disks is the first step in an ongoing project to preserve and catalog the museum's early recording collection. Stephens says applications of the technology might someday be used to recover sound from an even earlier period.

The museum houses a collection of about 400 of the earliest audio recordings ever made, which used materials such as rubber, beeswax, glass, tin foil, and brass, according to Stephens.

"There are surviving samples of tin foil recordings from Tom Edison in 1877," Stephens says. "There are even older sound phonautograms from 1859, but those were never intended to be played but show sound recorded in waves."

Stephens is excited about the future of the technology. "These recordings are part of the birth of our technologies to record and play back sound," she says. "How we got to where we are, these episodes are fascinating. We hope that this technology will become widely available for recordings that are in desperate need of preservation. There are many commercial recordings that are at risk of being lost."