Guidelines: Audio Digitization System Performance
Audio-Visual Working Group

Performance of audio digitization systems: overview. The Working Group has been exploring the issues pertaining to the performance testing of audio digitization systems. This activity responds to recommendation 2.4 of the National Recording Preservation Plan and parallels efforts by the Still Image Working Group to develop metrics and methods for the performance testing of still image scanners and cameras. These projects are supported by the Working Group’s expert consultant Chris Lacinak of AVP.

The exploration was carried out in three separate activities, two of which entailed the development of guidelines:

1. Analog-to-digital converters (ADCs): high-level performance metrics and measurement.

This activity yielded a guideline that features twelve pass-fail aim points for ADCs together with recommended methods for measuring that performance. These aim points represent the desired level of performance for preservation digitization. The measurement of performance at this level requires expensive test equipment and advanced engineering skills.

Introduction and links to high level guideline and other resources

2. Analog-to-digital converters (ADCs): metrics and measurements at low cost.

As noted above, the testing of ADCs to demonstrate high level performance requires expensive equipment and advanced engineering skills. In order to serve modestly resourced preservation facilities, the Working Group developed an approach that reduced both the cost for testing and the need for staff with advanced skills. This guideline features seven pass-fail aim points and the Working Group offers an open-source application that can be used with low-cost test equipment.

• Introduction and links to low cost guideline and other resources
• ADCTest downloads and resources *As of October 2024, ADCTest is no longer supported or maintained by FADGI.*

3. Performance impairments caused by interstitial errors.

Interstitial errors consist of lost or altered samples within the recorded file, resulting in the loss of content and integrity. These errors--often very momentary--result from a failure in one or more of the interfaces that carry digital data, e.g., the handoff from the ADC to the digital audio workstation (DAW), and in the DAW's writing of the file to a storage medium.

Introduction and links to consultant reports

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.