Extended Audio Description for Videos

Some videos present critical visual information during moments with continuous dialogue or rapid scene changes. When extended audio descriptions are not provided, people who are blind or have low vision cannot perceive essential visual details, such as on-screen actions, scene changes, text overlays, or visual cues that are not otherwise conveyed through audio.

As a result, these users are unable to fully understand the video content, context, or intent, leading to an incomplete and inequitable viewing experience compared to sighted users.

Standard audio description fits narration into existing pauses in dialogue. Extended audio description is different: it pauses the video at key moments to provide longer, detailed narration before resuming playback. This allows time to describe complex visuals like diagrams, gestures, or scene changes that can’t fit into normal pauses in dialogue.

Example

A physics professor gives a lecture while sketching equations on a whiteboard.
He talks quickly, erases drawings, and moves from one problem to the next without pause.
In the extended audio description version, the video is paused after each problem.
The narrator describes the professor’s drawings, gestures, and diagrams in detail before the lecture continues.

Here, the pauses make it possible for the viewer to fully understand both what is said and what is shown.

WCAG Success Criterion

1.2.7 Extended Audio Description (Prerecorded) – Level AAA
When there are not enough natural pauses in a video’s audio track to include standard audio descriptions, extended audio descriptions must be provided for all prerecorded synchronised media.

Key points:

• The video temporarily pauses to allow the narrator to describe important visuals.
• The presentation then resumes once the narration finishes.
• Users should be able to turn this feature on or off, or have access to a separate version with it included.

Why This Matters

Standard audio description works only when there are gaps between dialogue or sound effects.
In fast-paced or information-heavy videos, there may not be enough space to include meaningful descriptions.

Extended audio descriptions ensure that users who rely on them don’t miss any visual information like diagrams, movement, or on-screen text that’s essential to understanding the content.

Without them, a user might hear the lecture but miss key visuals, like the formulas or charts being referenced. With them, every visual detail can be described clearly without rushing or overlapping the speaker’s voice.

When You Should Use It

You should add extended audio descriptions when:

• The video includes continuous speech or background sound with few pauses.
• The visual information changes quickly or includes detailed elements that need more time to describe.
• The viewer needs to understand drawings, charts, gestures, or other non-verbal cues.

Examples include:

• Lectures or tutorials with heavy visual content
• Demonstrations or experiments
• Action scenes or sequences with constant movement

How to Add Extended Audio Descriptions

There are several methods for creating and delivering extended audio descriptions:

1. Pause and Narrate Approach
   Edit the video to insert pauses at appropriate points, allowing the narrator to describe visual details.
   The video then resumes once the narration ends.
2. Alternate Version of the Video
   Create two versions of the video, one standard and one with extended audio description.
   This prevents disruption for users who do not need the feature.
3. Toggle Feature in Media Players
   Offer the ability to turn extended descriptions on or off within the media player interface.
   This gives users flexibility based on their preferences.

Bad Practices

• Not adding pauses where needed
  Important visuals go undescribed because there’s no time for narration.
• Overlapping narration and dialogue
  The description plays over speech, making both difficult to understand.
• No user control
  The extended description version cannot be turned off or is hard to find.

Good Practices

When adding extended audio descriptions:

• Write clear, descriptive narration that complements the existing audio.
• Keep pauses natural and maintain the pacing of the video.
• Use professional narrators familiar with describing visual details.
• Label versions clearly (for example, “Video with Extended Audio Description”).

Ask yourself:

• Are there long sections of dialogue that leave no time for description?
• Is the visual information complex or detailed enough to require extra narration?
• Can users easily access or disable extended descriptions?

Wrapping Up

Extended audio descriptions make dense, fast-paced videos accessible for people who are blind or have low vision and let them fully grasp the visual meaning that would otherwise be missed.

By pausing the video to include detailed narration, you meet WCAG Success Criterion 1.2.7 Extended Audio Description (Prerecorded) and ensure that all viewers can experience your content completely.

Without extended descriptions → “I hear what’s being said, but I can’t picture what’s happening.”
With extended descriptions → “I understand every detail of what’s being shown and explained.”

Providing extended audio descriptions isn’t just about compliance, it’s about giving everyone equal access to information and learning.