WCAG confusion around audio description

30 July 2019

Parts of the Web Content Accessibility Guideline 2.0 (WCAG 2.0) can be difficult to understand, especially if you're rapidly trying to get your head around it and apply it before your website or article is launched to the public.

Some success criteria can be more confusing than others, or even seem to merge together, such as how to make your multimedia content accessible to people who are blind or have low vision.

What is audio description?

Most people have heard of captioning, the text on a video that repeats dialogue or sounds. However, audio description is much less known.

While captioning was designed for the deaf or hearing impaired, audio description is designed for people who are blind or have low vision.

A video with audio description will have a separate audio track, or narrator, who describes what is visually happening on the screen. If you haven’t seen in it in action before, check out this audio described clip of popular children’s film Frozen.

When to audio describe?

A video only requires audio description if there is something that needs to be audio described. If a video shows the Australian Prime Minister delivering a speech, then audio description is not required as the primary content is already provided through the dialogue.

These are known as talking head videos.

However, if that same video had text on screen that wasn't described by the audio, or if the Prime Minister pointed to an object but didn't refer to it in his speech, then the information would not be perceived by someone who is blind or has low vision and audio description may be required.

What does WCAG say about audio description?

WCAG 2.0/2.1 has three different levels of conformance when it comes to audio description; level A, level AA and level AAA. This is where the confusion starts.

Common among all levels of WCAG is that an audio described version of a video can be provided either by enabling it using a button on a video player, having it on the video by default, or providing a completely separate video which is audio described on the same page or a nearby hyperlink (as long as it's clearly labelled as being audio described).

Level A

The Level A version, also known as 1.2.3 Audio Description or Media Alternative (Prerecorded), allows for the most flexibility. It provides the content author with a choice on how to make their video accessible to people who are blind or have low vision.

If a video has visual content not described by the audio, then you can provide an audio description or a media alternative. In all cases, a media alternative is a text transcript.

A text transcript not only details the video dialogue in text form but also includes important visual content found in the video. It is similar to a movie script, where you mention when actors enter or leave the scene and events that occur in the scene.

A live example of this can be found on the National Film and Sound Archive website, where they included a transcript for a Crocodile Dundee video nested neatly within an expandable accordion section.

Text transcripts provide unique advantages when compared to audio description. For one, they allow the video to be perceived by people who are deafblind as they cannot make use of captioning or audio description alternatives.

Some people also prefer to read a text transcript regardless, as it can allow them to absorb the information in the video in a shorter amount of time or quickly scan to the section they are most interested in.

When examining to see if your video meets 1.2.3 Audio Description or Media Alternative, follow the flowchart below:

Flowchart for how to test 1.2.3 Audio Description or Media alternative. Long Text description provided below.

Long text description of 1.2.3 Audio Description or Media Alternative flowchart:

  1. Locate a video
  2. Does the video have important visual elements not described in the dialogue already? If no, the video passes and no audio description is needed. If yes, continue to step 3.
  3. Is accurate Audio description available? If yes, the video passes. If no, continue to step 4.
  4. Is a media alternative (e.g. Text Transcript) available that describes visual elements? If yes, the video passes. If no, the video fails.

Level AA

1.2.5 Audio Description (Prerecorded) is slightly stricter in that it doesn't allow the content author to simply include a text transcript with the video to pass the guideline. This means if there is visual content in the video that needs to be described and there are enough gaps in the dialogue of the video to squeeze in audio description, then audio description must be provided.

Level AA has a quirk though. If you provide audio description for a video, then you don’t need to also provide a text transcript. This is unfortunate, as text transcripts are the only way that deafblind users can perceive video content and includes other benefits mentioned earlier. Providing a transcript along with your audio description doesn't become a requirement until you start looking into the level AAA success criteria.

Vision Australia strongly recommends all video content have a text transcript to make content accessible for people who are deafblind. If for technical reasons only an audio description or text transcript can be provided, the text transcript is the most important although this may not strictly meet WCAG.

As with all success criteria in WCAG, passing the level AA success criteria doesn't necessarily mean you meet the level A success criteria, so the following flowchart has a fallback to the 1.2.3 flowchart.

Flowchart for how to test 1.2.5 Audio Description. Long text description provided below.

Long text description of 1.2.5 Audio Description flowchart:

  1. Locate a video
  2. Does the video have important visual elements not described in the dialogue already? If no, the video passes and no audio description is needed. If yes, continue to step 3.
  3. Is accurate Audio description available? If yes, the video passes. If no, continue to step 4.
  4. Does the video have room (gaps between dialogue) for an audio description to be included? If yes, the video fails. If no, the video passes, but you still need a media alternative to meet the level A success criteria.

Level AAA

The lesser known level AAA success criteria, 1.2.7 Extended Audio Description (Prerecorded), requires you to provide pauses in your video to allow a narrator the time to describe the visual content, assuming there isn't already breaks within the dialogue of the video.

This success criterion is the strictest, as any video that has important visual elements that are not already described in the audio must have an audio description, with no exceptions.

Level AAA also requires you to provide a text transcript (under 1.2.8 Media Alternative). This is required for all videos and ensures that people that are deafblind will be able to perceive your video content.

The flowchart for 1.2.7 Extended Audio Description is more straight-forward than the A and AA versions:

Flowchart for how to test 1.2.7 Audio Description Extended. Long Text description provided below.

Long text description of 1.2.7 Extended Audio Description flowchart:

  1. Locate a video
  2. Does the video have important visual elements not described in the dialogue already? If no, the video passes and no audio description is needed. If yes, continue to step 3.
  3. Is accurate audio description available? If yes, the video passes. If no, the video fails.

Final tips

Audio description, while being lesser known, is vitally important to allow users who are blind or have low vision to appreciate multimedia content. Text transcripts extend this reach to the deafblind community as well.

Follow the tips below and many 'talking head' videos can avoid the need for a separate audio described version of your video:

  • Ensure your speakers describe the visual-only content they refer to in their dialogue.
  • Have your speakers or an announcer introduce the name and profession of the speaker, instead of relying on text on the screen.
  • If you have a narrator in your video, get them to also state any text on the screen, which is commonly seen for intros, interview questions or outros.

If you write a script for your video before creating it, it can be converted into a text transcript with little effort and will have the benefit of making your video accessible for deafblind users.

Using these flowcharts and tips, you can ensure your video content is accessible for people who are deafblind, blind or low vision and meets Australian web accessibility standards.

In Australia, several disability groups (including Vision Australia) are calling for more audio description on TV, which will hopefully one day lead to audio description being just as widespread and well known as captioning.