Restoring and Preserving Historical Audio Recordings
Ongoing partnerships between Lawrence Berkeley National Laboratory, the U.S. Library of Congress, and the Smithsonian Institution have enabled the restoration of many historically-valuable recordings.
The invention of the phonograph in 1877 enabled sound to be recorded for the first time. As inventors experimented and further developed this new capability, they made recordings using a variety of methods and materials, including tin foil, wax and plastic cylinders, and vinyl discs. Today, extensive recorded sound collections exist in archives around the world, but many of these recordings are fragile, damaged, or at risk of deterioration, and in some cases the technology used to record and play back audio from these recordings no longer exists. An alternate approach is needed to restore and preserve these valuable recordings.
This preservation challenge was addressed by a HIBAR research project launched by Dr. Carl Haber at Lawrence Berkeley National Laboratory. He became interested in this challenge after listening to a National Public Radio story that described how fragile historic audio recordings are likely to be damaged if someone plays them by dragging a needle over their surfaces. He wondered if it would be possible to retrieve the audio information without touching the delicate surface. Intrigued by this idea, Dr. Haber and a research colleague, Vitaliy Fadeyev, adapted their earlier work in creating detectors for particle physics experiments to develop a non-contact digital imaging system for this purpose.
The imaging system, known as IRENE, uses a high-powered microscope that follows the groove path on an audio recording disc or cylinder and prepares a detailed spatial mapping of the groove. This spatial data is then processed with software that converts it into a digital audio file. The non-contact approach is particularly well suited to safely “play” fragile sound recordings, and it can be used to recover recordings that were designed to be played on devices that are now obsolete.
Following the successful initial proof of principle work at Lawrence Berkeley National Laboratory, the approach has been developed and tested through collaborative efforts with a number of partners, including the Library of Congress and the Smithsonian Institution. IRENE is currently in use by a number of archives and institutions to preserve and digitize their historical audio records, and is credited with restoring many historically valuable recordings, including the earliest known recording of a human voice, early recordings of the voice of Alexander Graham Bell, and recordings of lost indigenous languages.
The IRENE project embodies the characteristics of HIBAR research. The cross-sectoral leadership team included a diverse group of individuals with expertise in key areas, including archival science, history, physics, and engineering. In addition to enabling the discovery and development of new optical imaging capabilities, the project has preserved historically valuable information that was not previously accessible and at risk of being lost forever.