Understanding:Success Criterion 1.2.4: Captions (Live)

The intent of this Success Criterion is to enable people who are deaf or hard of hearing to watch real-time presentations. Captions provide the part of the content available via the audio track. Captions not only include dialogue, but also identify who is speaking and notate sound effects and other significant audio.

This success criterion was intended to apply to broadcast of synchronized media and is not intended to require that two-way multimedia calls between two or more individuals through web apps must be captioned regardless of the needs of users. Responsibility for providing captions would fall to the content providers (the callers) or the “host” caller, and not the application.

• People who are deaf or have a hearing loss can access the auditory information in the synchronized media content through captions.

• A Web cast

  A news organization provides a live, captioned Web cast.

• A music Web cast

  An orchestra provides Communication Access Realtime Translation (CART) captioning of each real-time Web performance. The CART service captures lyrics and dialog as well as identifies non-vocal music by title, movement, composer, and any information that will help the user comprehend the nature of the audio.

Resources are for information purposes only, no endorsement implied.

• See 1.2.2: Captions (Prerecorded).

Each numbered item in this section represents a technique or combination of techniques that the WCAG Working Group deems sufficient for meeting this Success Criterion. However, it is not necessary to use these particular techniques. For information on using other techniques, see Understanding Techniques for WCAG Success Criteria, particularly the "Other Techniques" section.