audio-caption

Ensures <audio> elements have captions.

Description

Each HTML5 audio element requires the track element, with the attribute kind="captions" set. For the advantage of users who are hearing-impaired, captions are text versions of the dialogue, narration, and any significant auditory information that is timed to match the audio file.

Why is it important?

Without a caption, hearing-impaired users are unable to understand the content of an audio file, including who is speaking, what is being said, and any non-speech information that is communicated through sound, such as musical cues or sound effects. The portion of the content that isn’t accessible through the audio track is provided in captions.

A video contains a lot of action besides speech. A visually impaired individual won’t have any trouble hearing the dialogue in a movie, but they will miss out on key visual elements. Audio captions that are added to a video’s audio track can make visual elements available. In an audio description, the narrator fills in silences and provides the background information needed to comprehend what is happening.

Examples

• Success:

  • The kind attribute of the track element contains the value "captions".

• Failure:

  • The kind attribute of the track element contains the value "subtitles".

How to fix?

Ensure the value “captions” is present in the track element’s kind property. Ensure the caption text content accurately communicates all pertinent audio information, including who is speaking, a dialogue transcript, musical cues, and sound effects.

Tags

cat.time-and-media, wcag2a, wcag121, section508, section508.22.a

References

• WCAG 1.2.1: Audio-only and Video-only (Prerecorded)
• Deque University: audio-caption
• Accessibility Insights: audio-caption
• Evinced Digital Accessibility Knowledge Base: audio-caption