Loeb Music Co-Authors Groundbreaking Report on Audio Preservation

Bruce Gordon
Bruce Gordon, Audio Engineer in Loeb Music Library’s Audio Preservation Studio, seen here examining a digitized audio file, co-authored the recently released Sound Directions report.

A new best practices report co-authored by Loeb Music Library staff is drawing both national and international attention for its comprehensive and candid approach to the field of audio preservation at both the curatorial and technological levels. Sound Directions: Best Practices for Audio Preservation provides solid grounding for institutions pursuing audio preservation either in-house or in collaboration with an outside vendor. A part of the Sound Directions project undertaken jointly by the Loeb Music Library at Harvard and the Archive of Traditional Music at Indiana University, this 168-page publication presents the results of two years of research and development funded by the National Endowment for the Humanities in the United States. This work was carried out by project and permanent staff at both institutions in consultation with an advisory board of experts in audio engineering, audio preservation, and digital libraries.

Audio preservation is vital to the survival of an enormous variety of recordings that are by turns cultural, educational, artistic, and documentary—the range covers everything from birdsong to court case depositions to poetry readings to academic lectures to musical performances. At Harvard, for instance, work is currently underway to preserve the Milman Parry Collection of Yugoslav Oral Epic Poetry, recordings of 20th century poets reading their own works, a collection of Iranian oral histories, and South Indian classical musical performances by major artists of the mid-20th century.

“In the recent past, audio preservation meant the maintenance of a physical object such as a grooved disc recording or an open reel tape recording,” says Bruce Gordon, Audio Engineer in Loeb Music Library’s Audio Preservation Studio and co-author of the Sound Directions report. “Before the original was in danger of deterioration, the curator would direct an audio technician to perform preservation transfers of the original recording onto a new magnetic tape—and each tape was in turn copied before it also was endangered.”

Unfortunately, says Gordon, multi-generational analog transfer accumulates noise and distortion. So true audio preservation was not practical, if even truly possible, until the development of high resolution digital audio that allowed technicians to copy items without loss of fidelity or increased noise. More recently, thanks to innovations in electronic data storage and a drop in the cost of large storage systems, true audio preservation is not only possible, but practical and cost effective.

“As a result,” continues Gordon, “audio preservation has evolved from the simple care of physical objects to a system or program of digitization, storage, and access as well as the retention and care of the original object. The complexity of preservation systems requires the curator to rely upon audio engineers, technicians, and information systems specialists to attend to the technical details."

Co-authored by Gordon and Mike Casey, Associate Director for Recording Services at IU, the Sound Directions report establishes best practices in many areas where they did not previously exist. This work also explores the testing and use of existing and emerging standards and includes chapters on personnel and equipment for preservation transfer, digital files, metadata, storage, preservation packages and interchange, and audio preservation systems and workflows. Each chapter is divided into two major parts: a preservation overview that summarizes key concepts for collection managers and curators, followed by a section that presents recommended technical practices for audio engineers, digital librarians, and other technical staff.

The publication is very detailed about discoveries at both Harvard and Indiana. “Our aim was to offer two real world examples of preservation programs and systems, and to provide the community with a set of realistic best practices based upon existing or emerging standards and upon our own experience,” says Gordon.

Gordon and Casey designed the report to be as user-friendly as possible, despite its necessarily technical bent. “Each major section contains a general overview aimed at the curator, followed by the best practices for the topics of that section,” explains Gordon. “Rationales are given for those best practices, followed by background material, and then the details of the work for the rabid technologist and the very curious curator. There are appendices for the essential but otherwise unwieldy information.”

For example, best practice no. 1, which calls on curators to use skilled audio engineers and technicians when preserving material, may seem self-evident but is particularly imperative considering the extreme fragility of some recordings. Institutions might be tempted to enlist the help of trained students to perform preservation transfers but using a professional is simply a wiser choice. “Although students can be trained, they typically do not have intimate knowledge of obsolete playback technologies and might compromise the quality of the transfer of a critically endangered object. The object may only be playable once before it is damaged beyond repair, so the curator must be aware of the true cost of unskilled labor,” explains Gordon.

Best practice no. 6 begins to get into the technical side of things: “Use the Broadcast Wave Format for the preservation of audio.” Gordon explains that this format is easily identifiable and playable by the largest number of audio software applications, and because the file can store metadata (data about the audio data) as well as the pure audio data. “We believe Broadcast Wave Files will have the longest useful life until that format itself becomes obsolete. Having all of our data in a single format will facilitate the inevitable migration to the next logical format.”

One of the biggest technical obstacles they encountered is a format of digital tape called DAT (Digital Audio Tape). “It was originally designed as a consumer format, but was widely adopted by the professional audio community and by ethnomusicologists for field recordings because of its compact form and ability to record up to two hours of CD-quality digital audio,” says Gordon. “It became a defacto standard for portable digital audio recording. This is unfortunate because it was not designed for robustness as a professional tape format should be.”

The tape is extremely thin and narrow and, with data recorded by a rotating head like that in a VCR, prone to tracking errors. Recordings are sometimes flawed, and a poorly stored tape may refuse to play years, months, or even days later. “Sadly, many archives put their faith in DAT as a storage medium for the preservation of audio,” says Gordon. “This is a problem that will continue to haunt us, and we consider DAT recordings to be of the highest priority for re-formatting.”

Although Gordon and Loeb Music attempted to come up with solutions for working with DATs, they met with limited success. “We recommend that DATs be reformatted ASAP, if possible,” says Gordon. “Since writing the document we have heard of several other methods of retrieving data off of DAT tapes that warrant investigation.”

Along with the report comes a suite of 40 pieces of software, designed at Harvard and overseen by David Ackerman, Audio Engineer in Loeb Music Library’s Audio Preservation Studio, who wrote approximately a third of the program code. The software enables audio engineers to streamline the preservation process and to remove the likelihood of human error from the mechanical aspects. It will be publicly available to the preservation community and, says Ackerman, and it should have the potential to help other institutions solve problems similar to those Harvard and Indiana have encountered.

“My expectation is that the report is going to reach a lot of organizations, both in the U.S. and internationally,” says Dave Ackerman. “The Library of Congress has called us to talk about the software and to say they want to get hold of it, so the impact is there.” The report is all the more valuable because it takes a candid look at Harvard’s and Indiana’s experiences, reporting on the failures as well as successes. “It would have been easy to write a report like this that whitewashes all the problems that you encounter. There was an effort from both institutions not to do that.”

Only a month after release, the publication has been downloaded nearly 1,200 times and each appendix at least 165 times � and some close to 300 times. The project team has also fielded requests for a print version.

The Sound Directions project began several years ago when Virginia Danielson, Richard F. French Librarian of the Loeb Music Library, and Daniel Reed, Director of the Archives of Traditional Music at Indiana University, discovered that their institutions shared a similar objective in moving forward responsibly with audio preservation. Discussions with NEH revealed that American granting agencies were concerned about standards and best practices within US institutions. They applied for and received funding and began their work by looking at standards developed in Europe and Australia. “We are certainly not a standards-creating organization,” says Danielson, “but we did think we could work on best practices, particularly using published documentation from IASA (International Association of Sound and Audiovisual Archives) as a point of departure.”

“The report has been very well received by IASA membership,” says Danielson, “and it is being circulated by the Coalition for Networked Information.” Richard Wright, Archive Technology Manager at the BBC Future Media & Technology program, wrote, "I was impressed with the clarity and especially the division between presentation of curatorial vs. technical guidance. I'm sure this is a tremendous contribution to audio preservation." A key technologist at the Library of Congress responded to receiving the report with "Yippeee!"

Danielson partly credits the seven-member advisory board that aided the Sound Directions project with its success. Composed of sound engineers with experience in academic institutions and with long-term audio storage, the board consulted with Harvard and IU throughout the project. “The board is a key reason why the report has a wide reach. In some cases they offered extensive comments which we then responded to or incorporated,” says Danielson. “I think that’s a major reason why the report has the appeal that it does.”

“We really tried to cast our net as broadly as possible, nationally and internationally, and put ourselves on the most solid ground we could in saying that these looked to us like the best practices,” says Danielson.

Sound Directions: Best Practices for Audio Preservation is available as a PDF.