SC 1.2.9 Level AAA WCAG 2.0
Audio-only (Live)
Live audio-only content — radio streams, audio-only conference calls, live podcasts — needs a real-time text alternative such as live captioning so deaf and hard-of-hearing users get the content as it happens.
What it asks
When a website streams live audio with no accompanying video — a radio show, an audio-only Spaces / Clubhouse session, a phone-in panel — there must be a synchronized text alternative provided live. This is the audio-only cousin of 1.2.4 (live captions for synchronized media).
How to meet it
- Use a live transcription service that pushes text to a visible feed alongside the audio player.
- Display the live text in a designated, scrollable region with enough contrast.
- Identify speakers — a transcript with no speaker labels is hard to follow when multiple people are talking.
- Provide a way for users to scroll back through the recent transcript without losing their place.
- For platforms that don’t support native live captions, embed a third-party CART feed (Streamtext, Ai-Media).
Common failures
- Live podcast streamed with no captions of any kind, transcript published only after the episode ends.
- Auto-transcription on the host’s machine but not surfaced to listeners’ browsers.
- Live transcript displayed in a tiny, non-scrollable widget that disappears the moment new text arrives.
- Speakers swap without labels, leaving the transcript ambiguous.
Why it matters
AAA, and the cheapest way to comply is to plan for live transcription up front rather than retrofit it. Most audio-only live streams skip this entirely. For public-broadcasting or government information lines, expect this to become a procurement requirement.