Standards, Best Practices, and
Principles for Audio Preservation
Mike Casey
Associate Director
Archives of Traditional Music
Indiana University
“…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
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Audio formats
Equipment (playback machines, test devices)
Repair parts
Playback expertise
Repair expertise
Tools
Supplies
Degradation/Obsolescence
How much time do we have?
15-20 years
 Less for some formats
 Degradation + Obsolescence = Impossible/Too
Expensive
 If we start now…to digitally preserve our holdings

Standards, Best Practices, and Principles
for Audio Preservation
Audio preservation guided by
Archival principles
Ethical considerations
Standards
Best practices
Strategies and Implementations
Why Use Standards and Best Practices?
Ensure Quality
Provide Philosophical/Ethical
Encourage Sustainability
Foster Interoperability
Support a Migration Path
Foundation
International Association of Sound and
AudioVisual Archives (IASA)
Task Force to establish selection criteria of
analogue and digital audio contents for transfer
to data formats for preservation purposes.
October, 2003.
Council on Library and Information
Resources/Library of Congress
for the National Recording Preservation Board
Capturing Analog Sound for Digital
Preservation:
Report of a Roundtable Discussion of Best
Practices for Transferring Analog Discs and
Tapes
European Broadcasting Union (EBU)
Broadcast Wave Format
EBU Technical Specification 3285
BWF—a format for audio data files in
broadcasting
Version 1, July 2001
Audio Engineering Society (AES)
AES31-3-1999
AES standard for network and file transfer of
audio—
Audio-file transfer and exchange—
Part 3: Simple project interchange
Audio Engineering Society (AES)
SC-03-06 Working Group
Working Group on Digital Library and Archive
Systems
Task Group SC-03-06-A
Metadata Harmonization
AES SC-03-06-A
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
Sound Directions
Digital Preservation and Access
for Global Audio Heritage
Indiana University and Harvard University
Phase I was an R&D project funded by NEH
Focus on preservation
www.dlib.indiana.edu/projects/sounddirections/
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
International Association of Sound and
Audioivsual Archives (IASA)
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
IASA-TC 04
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
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Mass storage systems
Data tape
Hard disk drives
Checksums—verification of data integrity
IASA TC 03 and 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
ATM Preservation Transfer Workflow
Project Audio Engineer
Project Assistant
Technical expert
Library Science/Archival and/or
content expert
Software
Scripts
Project Programmer
Software/script developer
Open Reel Tape Workflow
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
Preservation Transfer Workflow
Project Assistant Tasks with Automation
Project Assistant
Markers in files
Create index
Download copies
Of PM files
Script 1
Verify
checksums
QC
filename
QC
BWF
Name markers
Enter ATMC metadata
for Production Master
Script 2
Create processing history
instance for Production Master
Create Production
Master File
Create ADL for Pres master
Add metadata
to BWF
Parse Production
Master and
create checksums
Create ADL for Prod master
Upload to NAS
Verify checksums
QC Engineer
metadata
Create ATMC record
for Production Master
Serve coffee (black)
Open Reel Tape Workflow
Long-term Preservation
Create preservation package (SIP)
Ingest into preservation repository (Fedora)
On-going data integrity checking
Periodic migration
(Actual—bits stored in MDSS)
Components of an audio preservation package
Wrapper: METS file
Preservation Master Files
Derivative Files
Images of source recording and its container
Files for scanned
field notes or photos
taken by collector
Associated Metadata
Standards, Best Practices, and
Principles for Audio Preservation
Mike Casey
Associate Director
Archives of Traditional Music
Indiana University