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Guidelines: Imaged Audio Content

In 2023, the Library of Congress is beginning an exploratory project with the Northeast Document Conservation Center (NEDCC) and other potential partners to develop Federal Agencies Digital Guidelines Initiative (FADGI) specifications and guidelines for imaged audio content. This project will primarily focus on IRENE (Image, Reconstruct, Erase Noise, Etc.) technology, which involves non-contact optical scanning of original artifacts such as wax cylinders and lacquer discs. The output of this digitization process is a complex package of potentially changeable content which may include high-resolution 2D or 3D image files of the audio carrier, primary and access audio files, log and data files about processing and system settings as well as other files. This package allows researchers to listen and discover audio content without damaging the original physical artifacts.

While there are currently a limited number of IRENE devices in use, each of them produces a significant amount of output materials that are widely distributed within the digital preservation community making this an impactful project for the joint FADGI Still Images and AudioVisual working groups.

Project Goals

The goal of this project is to document technical file specifications and delivery package guidelines for non-contact imaged audio projects for a variety of audio carriers. Our vision is something manifest-like which explains, for a range of relevant audio carriers, what each component of the delivery package is, how it was created (aka log files, which plug-ins were used if appropriate, software versions, etc) and why the component is needed (what role does it play for this content package). Then we’ll be more specific that, for example, that the image file should be specific file format at a prescribed resolution with embedded metadata, that the log files should contain coding/process history data that explains the signal chain including plug-ins and software version numbers, that the audio outputs are at X sampling rate/bit depth, if there was upsampling or EQ applied or any other action. For each of these, FADGI will, where possible, map to existing standards and specifications and where gaps exist, FADGI will develop guidelines to fill those gaps.


  • Will this project compare/contrast the various systems for imaged audio? No. The project will not compare and contrast various imaged audio systems nor will it specify when one system might be better than another. Each has a place in the digitization landscape and they have different approaches for different reasons.
  • Will FADGI assess the performance of imaged audio systems for specific content types? FADGI has no opinion about which system performs better with specific content. This project will describe, if you are going to use imaged audio in your preservation workflow, THESE are the things you will want to receive and understand what they are and here’s why they are important.
  • Does FADGI endorse imaged audio over other options for digitization? FADGI also does not encourage the use of imaged audio over other digitization options, including stylus-based options. That’s really for each institution to decide what works for their content, financial budget, staff experience levels and more.

Draft Workplan

In order to meet this goal, project stakeholders will focus on the questions and areas for exploration listed below.

  • Identify the user community for imaged audio products. This includes current IRENE practitioners (such as the LC, NEDCC) and other organizations with collections materials that are suited for digitization using non-contact scanning.
  • Identify and describe the components of the non-contact scanning imaged audio package.
  • Document the scope of what non-contact scanning technology can and cannot produce.
  • Identify information from existing FADGI guidelines and other standards, specifications, and guidelines (such as those developed by the Audio Engineering Society, Association for Recorded Sound Collections, and International Association of Sound and Audiovisual Archives and more) that is applicable to imaged audio digitization.
  • Codify potential output packages for specific use cases for non-contact scanning (such as from a wax cylinder, aluminum transcription discs, shellac discs and more).

This page will be updated as the work progresses. Comments are always welcome via the FADGI Comment Form or by email to [email protected].

Subgroup Members

  • Peter Alyea, Library of Congress/Preservation
  • Hannah Rose Baker, Northeast Document Conservation Center
  • Hana Beckerly, Library of Congress/FADGI
  • Patrick Breen, Library of Congress
  • Frank Cunningham, Northeast Document Conservation Center
  • Rob Friedrich, Library of Congress/National Audio Visual Conservation Center
  • Fenella France, Library of Congress/Preservation
  • Julia Hawkins, Northeast Document Conservation Center
  • Bryan Hoffa, Library of Congress/National Audio Visual Conservation Center
  • Charles Hosale, Library of Congress/American Folklife Center
  • Kate Murray, Library of Congress/FADGI
  • Tom Rieger, Library of Congress/FADGI
  • Bryce Roe, Northeast Document Conservation Center
  • Melissa Widzinski, Library of Congress/National Audio Visual Conservation Center

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Working Groups

Still Image Working Group
This group is involved in a cooperative effort to develop common digitization guidelines for still image materials.

Audio-Visual Working Group
This group works collaboratively on common and sustainable technical guidelines, methods, and practices for digitized and born digital sound recordings and moving images.

Last Updated: 02/22/2023