Audio-only (Live)
Tier 1 · The normative floor
Baseline compliance
What the normative text of WCAG 2.2 requires, and nothing more. Only a failure of this tier is a WCAG failure.
The bare minimum
Live audio-only content, such as a live audio stream, has an alternative that presents equivalent information.
Normative text
Verbatim from WCAG 2.2, W3C Recommendation 12 December 2024. Underlined terms are defined below.
An alternative for time-based media that presents equivalent information for live audio-only content is provided.
Definitions used (3)
Glossary definitions are normative. Their notes are informative.
- alternative for time-based media
-
document including correctly sequenced text descriptions of time-based visual and auditory information and providing a means for achieving the outcomes of any time-based interaction
Informative notes (1)
A screenplay used to create the synchronized media content would meet this definition only if it was corrected to accurately represent the final synchronized media after editing.
- live
-
information captured from a real-world event and transmitted to the receiver with no more than a broadcast delay
Informative notes (2)
A broadcast delay is a short (usually automated) delay, for example used in order to give the broadcaster time to cue or censor the audio (or video) feed, but not sufficient to allow significant editing.
If information is completely computer generated, it is not live.
- audio-only
-
a time-based presentation that contains only audio (no video and no interaction)
Tier 2 · The gap
Usability & user impact
Where content can meet this criterion and still make things harder for people with disabilities. These are not failures of SC 1.2.9, so raise them as usability defects. Known failures, including failures of related criteria, are listed in Tier 1.
A text summary posted afterwards doesn't help people following the event live.
Tier 3 · The golden path
Recommended best practice
The pattern that meets the floor, closes the gap, and avoids audit disputes. A recommendation, not a requirement.
Provide a live text stream from a human captioner, and publish a corrected transcript afterwards.
W3C's Understanding document and techniques for SC 1.2.9 ↗ are informative: sufficient techniques show ways to pass, and documented failures show common ways to fail, but neither changes what the criterion requires.
How SC 1.2.9 maps to the WCAG 3 draft
From this site's reviewed map to the WCAG 3 editor's draft. It's an interpretation: W3C has not published a mapping.
Successor provisions
From WCAG 2.2, section 5.1: “The main content of WCAG 2.2 is normative and defines requirements that impact conformance claims. Introductory material, appendices, sections marked as "non-normative", diagrams, examples, and notes are informative (non-normative). Non-normative material provides advisory information to help interpret the guidelines but does not create requirements that impact a conformance claim.”