Definition for WCAG 2.0 success criterion 1.2.3
1.2.3 Audio Descriptions or Media Alternative (Prerecorded): An alternative for time-based media or audio description of the prerecorded video content is provided for synchronized media, except when the media is a media alternative for text and is clearly labeled as such.
The intent of this Success Criterion is to provide people who are blind or visually impaired access to the visual information in a synchronized media presentation. This Success Criterion describes two approaches, either of which can be used: an alternative for time-based media and an audio description.
An alternative for time-based media provides all information (and any interaction, if present) of a synchronized media presentation in a more traditional text-based format. This generally takes the form of a separate page or view. An example would be a complete transcript of an audio/video presentation, which includes not only the spoken audio, but also accurately described any relevant information and actions taking place in the video, as well as any meaningful sound cues, song titles (if the choice of song conveys a particular meaning), music description (if the type or mood of the music is meaningful; for example '[Suspenseful music]').
An audio description is a specifically made audio track which, in addition to the regular audio elements of the media presentation, describes any meaningful visual aspects of the synchronized media presentation - this includes visible text, key visual elements such as graphics superimposed over a video (e.g. an arrow pointing to a UI element or a box around a group of UI elements), actions taking place in a video, or animations in an animated SVG diagram. This can be provided in various forms, ranging from an alternative audio track that a user can enable, a separate video file (in the case of a self-contained audio/video presentation), or a completely separate page with the synchronized media presentation which incorporates the audio description.
For a good example of audio description, see YouTube: MSFTEnable - Introduction to Disability and Accessibility (audio described version), which includes audio description in the natural pauses of the regular narration track in the segments between 3:26 and 11:10.
Note: if all the visual information in a synchronized media presentation (such as a video) is provided as part of the regular audio track, no additional audio description or alternative for time-based media is necessary. In this case, or if the page itself contains no synchronized media presentation, this criterion is marked as not applicable.
Testing success criterion 1.2.3
Input into spreadsheet
- Fail
- Time-based media does not have an adequate audio description. Record the nature of the failure:
- An alternative for time-based media or an audio description is not provided for all synchronized media presentations present.
- Although present, the alternative for time-based media or audio description is not accurate and does not includes a description of all meaningful visual aspects of the synchronized media presentation.
- In the case of an alternative for time-based media, the alternative does not include all speech and meaningful sound cues.
- In the case of an audio description, the audio description is not correctly synchronized with the visual aspects of the synchronized media presentation.
- Pass
-
- An alternative for time-based media or an audio description is provided for all synchronized media presentations.
- The alternative for time-based media or audio description is accurate and includes a description of all meaningful visual aspects of the synchronized media presentation.
- In the case of an alternative for time-based media, speech and any meaningful sound cues are included.
- In the case of an audio description, the audio description is correctly synchronized with the visual aspects of the synchronized media presentation.
- N/A
- The sample has no time-based media that requires an audio description.
How to test
- Manually verify that for all synchronized media presentations present, either an alternative for time-based media or an audio description is provided.
- Verify that the alternative for time-based media or audio description is accurate and includes a description of all meaningful visual aspects of the synchronized media presentation. This includes any information / text shown at the beginning and end of the presentation (such as title sequences, credits, production notes, copyright notices).
- In the case of an alternative for time-based media, verify that the alternative also includes an accurate alternative of speech and any other meaningful sound cues.
- In the case of an audio description, verify that the audio description is correctly synchronized with the visual aspects of the synchronized media presentation.
In the following screenshot, an audio description describes animations that are being drawn on the screen to annotate Laura's desire to be an actor.
