Mike Casey Associate Director Archives of Traditional Music Indiana University Standards, Best Practices, and Principles for Audio Preservation

“…it is alarming to realize that nearly all recorded sound is in peril of disappearing or becoming inaccessible within a few generations.” --National Recording Preservation Board in “Capturing Analog Sound”

“in the mid- to long-term there is a major risk that carrier degradation combined with playback obsolescence will defeat the efforts of archivists…” --International Association of Sound and Audiovisual Archives

The Time-Based Media Problem (Audio and Video ) Large Numbers Degradation Obsolescence Short time window

By the Numbers Indiana University Bloomington More than 569,000 audio, video, and film More than 364,000 (64%) are audio recordings 96,000 (27%) are unique 48,000 (13%) are rare 144,000 unique or rare audio recordings at IUB!

Degradation Chemical (chemical changes such as tape binder issues) Biological (living organisms such as fungus) Mechanical (changes in size and shape) Handling (disc scratches, chemicals from hands) Many caused or exacerbated by environmental storage conditions

Obsolescence Audio formats Equipment (playback machines, test devices) Repair parts Playback expertise Repair expertise Tools Supplies

Degradation/Obsolescence How much time do we have? years Less for some formats Degradation + Obsolescence = Impossible/Too Expensive If we start now…to digitally preserve our holdings

Audio preservation guided by  Archival principles  Ethical considerations  Standards  Best practices  Strategies and Implementations Standards, Best Practices, and Principles for Audio Preservation

 Ensure Quality  Provide Philosophical/Ethical Foundation  Encourage Sustainability  Foster Interoperability  Support a Migration Path Why Use Standards and Best Practices?

 Task Force to establish selection criteria of analogue and digital audio contents for transfer to data formats for preservation purposes. October, International Association of Sound and AudioVisual Archives (IASA)

Capturing Analog Sound for Digital Preservation: Report of a Roundtable Discussion of Best Practices for Transferring Analog Discs and Tapes Council on Library and Information Resources/Library of Congress for the National Recording Preservation Board

EBU Technical Specification 3285 BWF—a format for audio data files in broadcasting Version 1, July 2001 European Broadcasting Union (EBU) Broadcast Wave Format

AES standard for network and file transfer of audio— Audio-file transfer and exchange— Part 3: Simple project interchange Audio Engineering Society (AES) AES

Working Group on Digital Library and Archive Systems Task Group SC A Metadata Harmonization Audio Engineering Society (AES) SC Working Group

What is it:  Developing the emerging AES standard for technical metadata  Not yet released to the public  XML schema for collecting metadata on source audio object, derivative audio objects (files), and the digitizing process AES SC A

 Indiana University and Harvard University  Phase I was an R&D project funded by NEH  Focus on preservation Sound Directions Digital Preservation and Access for Global Audio Heritage

Best Practices  Personnel and Studio Signal Chain  Digital File Characteristics, Uses, and Functions  Use of Broadcast Wave Format  Interim Storage  Collection of Technical Metadata Sound Directions Digital Preservation and Access for Global Audio Heritage

Best Practices  Quality Control  Creation of Preservation Packages  Interchange of Preservation Packages Sound Directions Digital Preservation and Access for Global Audio Heritage

 IASA-TC 03 The Safeguarding of the Audio Heritage: Ethics, Principles and Preservation Strategy. Version 3, December 2005  IASA-TC 04 Guidelines on the Production and Preservation of Digital Audio Objects, Second Edition International Association of Sound and Audioivsual Archives (IASA)

What it is—TC 04:  Detailed set of best practices for audio preservation  The primary work in this field  Foundation of audio preservation programs  Developed by IASA Technical Committee  Over 20 international experts with audio preservation experience IASA-TC 04

What it covers—TC 04:  Overview of key digital principles and standards  Metadata  Signal extraction from originals  Preservation target formats and systems  Small-scale approaches  Optical discs IASA-TC 04

Signal extraction (playback)  Required for audio preservation engineers  Divided by format—  Cylinders, field and commercial discs  Analog magnetic tape, digital magnetic carriers  Optical disc IASA-TC 04

Signal extraction (playback) details  Selecting the best copy  Cleaning and carrier restoration  Characteristics of appropriate playback machines  Characteristics of recorded signal on format  Playback equalization  Typical preservation problems IASA-TC 04

Preservation target formats and systems  Principles of digital preservation  OAIS and basic functions  Trusted Digital Repositories  Archival storage  Mass storage systems  Data tape  Hard disk drives  Checksums—verification of data integrity IASA-TC 04

A few selected specifics:  Use file formats in a computer storage environment  Digital storage for technical, economic reasons  Follow international standards  Optimal playback is key  Preservation master files unmodified or unaltered IASA TC 03 and TC 04

A few selected specifics:  No permanent storage solutions→migration  CD and DVD are not appropriate long-term preservation choices—interim solution with testing  Format obsolescence and unavailability of replay equipment a great threat IASA TC 03 and TC 04

A few selected specifics:  Target format.wav or BWF  24/48 transfers at least—many using 24/96  A/D converter most critical component in digital pathway  Data reduction (compression) inappropriate for preservation files IASA TC 03 and TC 04

A few selected specifics: Collect a rich set of preservation (technical) metadata:  Details about the original carrier including its state of preservation  Details about copies produced from the original  Details on digitizing process including equipment, parameters and operators IASA TC 03 and TC 04

A few selected specifics:  No uncorrectable errors  Check regularly for data integrity  Refreshment and migration  Disaster plan—model threats  Multiple copies in separate locations IASA TC 03 and TC 04

Project Audio Engineer  Technical expert ATM Preservation Transfer Workflow Project Assistant  Library Science/Archival and/or content expert Project Programmer  Software/script developer Software Scripts

Collection Digitization Plan  Technical team meeting  Review collection documentation and condition  Discuss possible technical and preservation problems  Discuss default metadata Open Reel Tape Workflow

Preliminary Transfers  Digitize 3-5 recordings  Stop for intense quality control of both files and metadata  Find mistakes before they propagate through collection  Final approval—full speed ahead Open Reel Tape Workflow

Digitization--Engineer  Playback machine calibration and alignment  Tape diagnosis—speed, track configuration, tape base and thickness, problems  Confirm 1:1 or parallel transfer  Wind tape, set levels, adjust azimuth  Begin play Open Reel Tape Workflow

Digitization--Engineer  Collect technical and digital provenance metadata  Software application—ATMC  Monitor transfer Open Reel Tape Workflow

Digitization--Engineer  Create Preservation Master Files  Complete, unaltered stream from playback machine  Carrier of raw material from transfer  No editing, signal processing, data reduction, gain manipulation, announcements (slates)  24 bit, 96 kHz Open Reel Tape Workflow

Digitization--Engineer  Spot-check file  Approves for overnight script Open Reel Tape Workflow

Digitization--Software  Overnight script  Embed ‘catastrophic’ metadata into BWF  Enter metadata in ATMC  Generate ‘checksum’ (MD5)  Copy files to interim storage Open Reel Tape Workflow

Project Assistant Preservation Transfer Workflow Project Assistant Tasks with Automation QC filename Verify checksums Create ADL for Pres master QC BWF QC Engineer metadata Markers in files Create index Create Production Master File Add metadata to BWF Parse Production Master and create checksums Create ATMC record for Production Master Create processing history instance for Production Master Download copies Of PM files Create ADL for Prod master Enter ATMC metadata for Production Master Upload to NAS Verify checksums Name markers Script 1 Script 2 Serve coffee (black)

Long-term Preservation  Create preservation package (SIP)  Ingest into preservation repository (Fedora)  On-going data integrity checking  Periodic migration  (Actual—bits stored in MDSS) Open Reel Tape Workflow

Preservation Master Files Components of an audio preservation package Derivative Files Associated Metadata Images of source recording and its container Files for scanned field notes or photos taken by collector Wrapper: METS file

Mike Casey Associate Director Archives of Traditional Music Indiana University Standards, Best Practices, and Principles for Audio Preservation