Hutchins Library
Special Collections & Archives

Hutchins Library
Special Collection & Archives
CPO LIB
859-985-3262

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Sound Preservation & Access
 
The sound recordings preservation and access program at Berea College's Hutchins Library began in 2006.

The program's focus is on Berea's collections of noncommercial recordings that document Appalachian history and culture and the history of Berea College. The recordings are especially strong in the areas of traditional music, religious expression, folklore, radio programs, College events, and oral history. Preserving these one-of-a-kind recordings is an urgent need because the open reel and cassette tape on which they are recorded is nearing the point of being unplayable due to age and scarceness of proper playback equipment.

In accomplishing the task of accurately and reliably preserving the recordings for the very long term, the program is guided by the recommendations of the International Association of Sound and Audiovisual Archives as set forth in IASA-TC04 Guidelines on the Production and Preservation of Digital Audio Objects: Standards, Recommended Practices, and Strategies.

Key elements of Berea’s preservation and access efforts include converting the original recordings to high resolution digital files, providing CD listening copies for Library use, and storing the digital files on a dedicated server which is backed up at remote locations. A searchable online database of collection contents and selected audio files are available through Hutchins Library’s Sound Archives Web Page.

Hutchins Library’s Audio Preservation Program Details
Audio Formats
Open Reel Tape
Cassette Tape
Playback Equipment & Procedures
Analog-to-Digital Process
Digital File Formats
Digital Preservation
Digital Access
Links to Related Sources

Audio Formats
Hutchins Library’s non-commercial sound recording collections consist of some 12,000 items. Those at highest risk are open reel and cassette audio tape, lacquer discs, and digital audio tape (DAT). Each format presents different requirements in terms of physical handling, playback equipment and procedures.

Open Reel Tape
The Library has approximately 4,500 open reel tapes. About 20% of them have an acetate base with the remainder being polyester. There are also a few paper-based tapes. Many of the open reel tapes are recordings of Berea College’s annual Celebration of Traditional Music dating from 1974. Other open reel tape collections include the folklore and traditional music field recordings of Leonard Roberts, William Tallmadge, Bruce Greene, John Harrod, and Barbara Kunkle and range in date from the early 1950s through the 1970s.

Acetate-based open reel tape is less stable than polyester and represents a higher priority for preservation copying. Acetate tape is eight times more sensitive to moisture in the air than polyester, leading to tape pack problems such as linear expansion, transverse warping (curling or cupping), windowing, etc.

Vinegar Syndrome is another problem that may be found with acetate tape. This condition, which is most common in acetate photographic film, is an autocatalytic decomposition process that produces acetic acid as a byproduct. Once started, the decomposition continues at an ever-accelerated rate. Archivists have recently identified Kodak audio tape from the 1960s as susceptible to this condition.

Some polyester tape dating from the mid-1970s to around 1990 is affected by what is known as Sticky Shed Syndrome. This condition is caused by breakdown of the tape binder by hydrolysis which leads to massive shedding and squealing when playing. Many of these tapes can be restored for playback through a heat treatment process, commonly called “baking,” that is now widely used in audio preservation work. Once baked, the tape must be transferred within a week or two before it begins reverting back to the sticky shed condition.

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Cassette Tape
The Library has approximately 3,500 non-commercial audiocassettes dating from the 1960s through the 1990s. Although once widely used for its convenience and economy, audiocassette tape is universally regarded as undependable for long-term stability and is a high priority for preservation copying. Older cassette tapes, particularly those from the 1970s and before, are often exhibiting preservation problems such as squealing and shedding due to loss of lubricant. While these symptoms are similar to those of Sticky Shed Syndrome, appropriate corrective measures are quite different and definitely do not include baking.

Playback Equipment and Procedure
The aim of preservation copying is to obtain the highest quality, most accurate representation of the aging original recording possible. For this reason preservation work at Berea is done with professional-level playback equipment that is properly calibrated and maintained. Equipment used in the Library’s sound preservation studio which is specially designed for critical listening, include a Studer A807 for open reel tapes and a Tascam 122MkIII for audiocassettes.

 
Studer A807
Tascam 122Mkll

There are several sets of technical procedures necessary for successful preservation copying of archival sound recordings. Among these are basic audio engineering methods along with techniques essential to optimal, accurate playback of aging tapes.

The use of appropriate procedures makes a measurable, significant difference in achieving the most accurate representation possible of the original recording. Included among these procedures are visual inspection, slow winding, replacing slotted reels, acid-free paper leaders, proper tape track configuration and playback speed, playback head azimuth adjustments and reproduction alignments.

Analog-to-Digital Process
For preservation, analog-to-digital conversion (ADC) should be handled by a converter separate from the computer, according to best practices document, IASA TC-04 Guidelines on the Production and Preservation of Digital Audio Objects. The associated sound card should then be capable of passing a digital stream without modification.

Berea College uses a Mytek Digital USA Stereo96 ADC/DAC in tandem with a Lynx Studio Technology LynxONE PCI interface card. Steinberg WaveLab 6 captures the digital signal as a high-resolution, 24-bit, 96 kHz PCM BWAV file. A monitor controller system allows for audio monitoring of pre- and post-digital conversion signal to guard against introduction of digital artifacts. The entire signal chain, both balanced analog and AES digital, uses Monster Cable Prolink interconnects.

Digital File Formats
According to IASA TC-03 The Safeguarding of the Audio Heritage: Ethics, Principles and Preservation Strategy, preservation transfer should produce master files that are unmodified, "without subjective alterations or improvements."

Creating and storing an unaltered, unmodified digital file means no editing of content. Every second on the source recording, no matter how irrelevant, is transferred in order to obtain a full, authentic representation of the original recording. This preserves content that future researchers may find important in ways that we cannot anticipate today. In addition, the original sound field, whether stereo or mono, is preserved in the master archival file.

Berea’s master archival sound files are 24-bit, 96 kHz PCM encoded BWAV files, more than twice the resolution of standard CD audio. This ensures that the full range of reproduced material is captured and preserved with utmost accuracy.

Derivative audio files are created for any form of editing, signal processing, or other alterations from the original preservation file. This includes making reference CDs for in-house listening, and encoding MP3 files for online access through the Sound Archives Web Page.

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Digital Preservation
Once high-resolution, unaltered archival master files are created, they are transferred to a dedicated high volume networked storage server. While this server acts (and even appears on the workstation desktop) as a huge hard disk drive (HDD), it is really a series of HDDs set up in a RAID (redundant array of independent disks.) As a precaution against data loss, the Sound Archives’ server files are backed up to remote network-attached storage devices (NAS) by the College’s Information Systems and Services.

Digital Access
Selected portions of the Berea's digitized recordings are available online via the following resources:

Links to Related Sources
Analog-to-Digital Process Playback Equipment Digital File Formats & Preservation