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Guidelines: Imaged Audio Packages

Starting in 2023, the Library of Congress began an exploratory project with the Northeast Document Conservation Center (NEDCC) and other potential partners to develop FADGI guidelines for imaged audio content. The resulting guidelines, first released for public comment in April 2024, primarily focused 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.

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.

Guidelines: Current Version

Guidelines for IRENE System Products for Long Term Retention: Deliverable Packages for Imaged Audio Systems (PDF 482 KB). Version 0.1. April 15, 2024. Draft released for public comment through June 1, 2024. After this date, the document will be considered Approved by the Working Group.

Please send comments to [email protected]. Comments and resolutions are documented in the FADGI Imaged Audio Comments table.

Project Scope

Starting in 2023, the Library of Congress began an exploratory project with the Northeast Document Conservation Center (NEDCC) and other potential partners to develop FADGI guidelines for imaged audio content. FADGI’s definition of imaged audio is “audio information reconstructed using non-contact optical scanning of grooved audio carriers.”

This guideline outlines the final package for audio content digitized through an imaged audio system. These are the files resultant at the end of the process, often handed off to the client. This document does not cover all files created or used during the process but rather the final results which should be maintained for the long term.

While much of this guideline is specific to the Project IRENE (Image, Reconstruct, Erase Noise, Etc.) system, the guideline can be applicable to other imaged audio systems as well.

For example, while the IRENE System produces a BigTIFF image file as a primary file deliverable, not all imaged audio systems do. If an imaged audio system does not produce an image file as part of its output, then the guidelines for the image file do not apply.

It’s a similar situation for raw data and log files. The guidelines advocate for the availability for process history and log files as part of provenance and transparency. The names of the specific files may be different in other systems but their usefulness is the same: to document how the deliverables were made, with what tools and with what actions both machine and human generated.


  • 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.

Subgroup Members (in alphabetical order)

Library of Congress:
Alyea, Peter
Beckerle, Hana
Breen, Patrick
France, Fenella
Friedrich, Rob
Hoffa, Bryan
Hosale, Charlie
McCollum, Steve
Mitrani, Sarah
Murray, Kate
Thatcher, Travis
Uhler, Reina
Widzinski, Melissa

Smithsonian Institution: 
Ankin, Alisha
Cutler, Alicia
Hockstein, Dan
Holland, Connie
Kurasz, Stephanie
Sanchez, Crystal
Stephens, Carlene
Wiggins, Kelsey

Project IRENE:
Cornell, Earl
Haber, Carl

Northeast Document Conservation Center (NEDCC):
Baker, Hannah Rose
Cunningham, Frank
Fleck, Karl
Hawkins, Julia
Roe, Bryce

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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: 04/18/2024