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Audio Digitization Workflow: The Presbyterian Church in Canada Archives

I am currently working on an audio digitization project with The Presbyterian Church in Canada Archives to fulfill the requirements for GLIS 689 Selected Topics, which is offered by the School of Information Studies at McGill University. This course allows students to explore a topic related to information studies by creating an individualized program.

The Presbyterian Church in Canada Archives has a collection of recorded interviews that have been conducted with ministers, missionaries, and church workers to understand their experiences working for the church. These oral history interviews are recorded on audio cassettes and date from 2000s. The Presbyterian Church in Canada Archives has agreed to work with me to digitize these oral history interviews, catalog the collection, and make a selection of the recordings available on their website. To begin the project, it was necessary for me to create a workflow for the digitization process. The following is the workflow I created for the project.

Step One: Re-housing and Storage

When digitizing audio cassettes, each tape should be inspected before it is played to check for apparent damage. Audio cassettes typically have a lifespan of 10-30 years. Place cassettes in new plastic containers if the original housing is missing, acidic or broken. If the original housing does not show signs of being acidic or broken, then leave the tape in its original housing. It is recommended to use Polypropylene audio cassette cases. Rehouse magnetic tapes in clearly labeled audio cassette boxes. Photocopy original cases if it contains information, either handwritten or printed, before discarding them to preserve this information. Audio cassettes should be stored vertically, not flat, and on any edge.

Step Two: Arrangement and Indexing

After getting the magnetic tapes into archival boxes, make an inventory of the collection. Record which boxes the tapes are now housed in before returning boxes to shelving area. While creating an inventory, determine which items are most at risk and are in greater need for digitization. If documentation is found in the collection, such as records that describe its creation or use like transcripts, inventories, or project proposals, the arrangement of the collection should maintain the relationship between the recordings and the documents. Documentation can be physically arranged separate from the magnetic tapes, and its relationship should be clearly expressed in the catalog description. At the file level, arrange recordings by interviewer name. At the item level, arrange recordings numerically by the date of the interview.

Step Three: Identification and Description

Equipment should be configured and tested before beginning digitization. Use an external audio cassette player that can be connected to the computer by USB. Use audio capture software such as Audacity to capture, store, and edit files. Create digitization logs or spreadsheets to track progress and record metadata. Audacity can be modified to embed additional metadata in audio recordings, such as genre = interview. Once the audio file has been recorded name files with a unique identifier and the name of the interviewer and interviewee. For example: A-1758-AC-01_Bob_Anger_Interview_with _James_Smith_1991.wav. The use of meaningful file names indicates the contents of the file, the date of creation, and the structural relationship between files. Digital files will be store on an external hard drive. Prepare audio cassette for digitization by:

  1. Removing write protection tab to make sure the tape is not accidentally recorded over
  2. Testing the movement of the reels by turning slowly with a pencil or finger
  3. Checking for damage to casing and repair or rehouse in new casing if necessary
  4. Check for damage to tape such as metal flakes coming off the tape, bunching or sticking in tape, folds or breaks in tape

Digitizing audio takes place in real time, digitization process will take the length of the tape plus edit and export time. Recommended archival quality for ingesting audio is a minimum sampling rate of 48kHz with 96kHz preferred, and a minimum bit depth of 24-bit with 32-bit preferred. Once digitized, audio tapes should be saved as uncompressed Waveform Audio Format (WAV) or Broadcast Wave Format (BWF) files for preservation copies and compressed Moving Picture Experts Group Layer-3 Audio (MP3) files for access copies. Capture a few moments of silence in beginning and end of recording and edit it out later so that portions of the recording are not missed. Items with no identification or poor labelling will be identified and described by listening to the recording in full. Magnetic tapes should be rewinded slowly at <381 mm/s or 15 inches/sec. Describe audio recordings at file level, where it is arranged by interviewer name. Describe audio recordings using Rules for Archival Description (RAD). In the description, specify the type of audio-visual material for example “Audio” for sound recording, “Moving Images” for video recording or motion picture film, and “Mixed materials” for audio visual materials found with other types of materials, or if sound and moving image are being described together. Information will be entered into an Inmagic DB/TextWork database that will be newly designed for audio recordings.

Example of file-level grouping:

Interviews with Bob Anger, 1992-1995
3 audio cassettes (3hr 30min)
Rev. Dr. Bob Blackburn, Moderator of General Assembly, 1992 (1hr)
Rev. David Bradford, Minister of St. Andrew’s PC, 1994 (1hr 30min)
Nancy Cox, Professor at Knox College, 1995 (1hr)

References

Hess, R., Iraci, J., & Flak, K. (2012). The Digitization of audio tapes – Technical Bulletin 30. Retrieved from https://www.canada.ca/en/conservation-institute/services/conservation-preservation-publications/technical-bulletins/digitization-audio-tapes.html

McShea, M. (2015, August 7). Guidelines for Processing Collections with Audiovisual Material [Text]. Retrieved August 21, 2019, from https://www.aaa.si.edu/documentation/guidelines-for-processing-collections-with-audiovisual-material

Sustainable Heritage Network. (2018). Audio cassette digitization Workflow (p. 5). Retrieved from https://sustainableheritagenetwork.org/system/files/atoms/file/Audio_Cassette_Digitization_Workflow.pdf

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