Version: WCAG 2.0 and up
Number: 1.2.9
Level: AAA
  • Audio

An alternative for time-based media that presents equivalent information for live audio-only content is provided.



The purpose of this success criterion is to ensure that user who have difficulty hearing a live audio event can still follow what is going on.

How to Meet

To meet this criteria, real-time captioning needs to be provided for any live audio events (e.g., an audio conference with an author).


Ebook formats typically do no support live streaming of audio, so meeting this requirement is not practical in most cases.

If authors or publishers host live streaming events, they typically do so using a platform specialized for such events. Including a link to such an event within a publication does not require the event be accessible for the publication to be accessible.

Additional Information

The knowledge base does not currently include information on live-streaming audio content due to the lack of implementation in publishing formats. Refer to the WCAG guidance documents for additional information.