Introduction to Audio Descriptions

Introduction:

Audio description is an accessibility feature that provides spoken narration of important visual content in video or graphical multimedia. Audio descriptions help ensure that listeners who are blind or have low vision can access information that is presented visually but not conveyed through dialogue, narration, or other audio elements.

In higher education, audio descriptions support equitable access to visual elements in instructional videos, recorded lectures, demonstrations, simulations, and multimedia learning materials. Educational videos and graphics are required to have audio descriptions to be fully accessible and compliant with WCAG 2.1 AA SC 1.2.5, part of the Title II standards.

For faculty and instructional designers, the goal is to ensure that listeners who cannot see the screen receive the same essential information and learning experience as those who can view the visual content.
This can often be achieved through thoughtful video design, descriptive narration, and when necessary, standard or extended audio description tracks.

There are multiple methods you can use to ensure that all learners have access to the visual content in your presentations.

  1. In your initial lecture recording or presentation, ensure that you are describing any visual elements from your slides as you give your presentation.  
  2. For lectures that are already recorded:
    • Create an Extended Audio Description (EAD) to accompany the recorded video that fully describes the visual content being presented.
    • Provide listeners with a fully accessible slide presentation that they can review through a screen reader, and provide audio cues that indicate which slide is currently being presented in the video.
    • Create a Standard Audio Description (AD) to accompany the recorded video that describes the visual content being presented.

Note that you do not have to provide descriptions for images that are used as decorative images, for visual variety, background images, or redundant visual information.

This document provides basic definitions of EAD and AD, and addresses how to implement these solutions for educational materials.  This document is focused on the most common type of educational video, the recorded lecture (either a voice over slide presentation, or a lecture captured from within a classroom) and on using the MyMedia platform to deliver your videos.

If you have videos that use a different instructional method - for example software instruction through screen capture, or a video walk-through of a complex visual model, please contact _______________ to plan an approach to remediate these videos. 

 

Table of Contents:

 

Types of Audio Description:

There are two primary types of technologies that can be used to provide additional audio description:

  1. Extended Audio Description (EAD)
  2. Standard Audio Description (AD)

 

Extended Audio Description (EAD)

Extended audio description delivers extended descriptions of video visuals by pausing the main video and reading a text description of the content. Use EAD when natural pauses in the video do not provide enough time to adequately describe important visual information. In these situations, the video player temporarily pauses while providing an additional audio description through a Video Text Track file. Once the description is complete, the video resumes.

The user's computer voice-over functionality provides the audio description by reading a specially formatted Video Text Track or .VTT text document provided by instructors or subject matter experts. Listening to the audio track is optional for the user, similar to how they can enable or disable closed captions. The .VTT text document is attached directly to the recorded video lecture in the OU MyMedia platform and uses the same editing workflow as closed captioning.

This approach allows significantly more detail to be communicated without rushing the narration.

Here are a few examples of a video with an Extended Audio Description track:

  •  
  • This video walks through the basics of audio description and provides examples of visual slides that include appropriate extended descriptive tracks—note, the descriptive slides start at 1:22.
    • This video also demonstrates the EAD functionality of videos hosted in the OU MyMedia platform.
    •  
  • Extended Audio Description - Ai-Media Example [AD]

EAD is the recommended approach for multiple reasons:

  • Since it uses a text-based document, you can create it at any time after the initial video recording and edit it as needed directly within the MyMedia platform.
  • The MyMedia player provides tools that allow listeners to manage their listening experience (e.g., enabling/disabling the AD track, skipping, or replaying a description). See the embedded video above for examples of the EAD playback tools.
  • Because the player pauses the video, you can cover visual content in extensive detail.

 

Standard Audio Description (AD)

Standard audio description inserts brief narrated descriptions during natural pauses in a video's existing audio.

The description track synchronizes with the video and uses available gaps in speech or other audio content to communicate visual information without interrupting the viewing experience. Unlike extended audio description, the main video never stops or stretches in length. AD is created as a separate recorded audio file that is added to the recorded video lecture in MyMedia.

Here are a few examples of a video with a Standard Audio Description track:

A Standard Audio Description track is not the recommended approach for multiple reasons:

  • Because it relies strictly on natural pauses in the video, it forces shorter descriptions that are often not extensive enough to fully illustrate the visual elements.
  • AD plays a separate recorded audio track alongside the video's original audio track, which can cause the AD audio to "talk over" existing dialogue.
  • The recorded audio track is also more difficult to create and edit if needed. The user must record an audio track that is timed to the pauses in the existing video. If the AD needs to be adjusted or edited,  a new audio track would need to be recorded and uploaded with any edits or changes.
  • The recorded audio track is also more difficult to create and edit if needed. You must record an audio track timed precisely to the pauses in the existing video. If the audio description needs to be adjusted or edited, a new audio track must be recorded and uploaded with any edits or changes.

 

Further Reading

There are additional articles on Audio Descriptions:

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