Techniques for WCAG 2.0

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# G157: Incorporating a live audio captioning service into a Web page

## Applicability

All technologies that present live audio-only information.

This technique relates to:

- Success Criterion 1.2.9 (Audio-only (Live))
  - How to Meet 1.2.9 (Audio-only (Live))
  - Understanding Success Criterion 1.2.9 (Audio-only (Live))

## Description

The objective of this technique is to use a real-time caption service to provide a text version of live audio content. Such services use a trained human operator who listens in to what is being said and uses a special keyboard to enter the text with only a small delay. They are able to capture a live event with a high degree of fidelity, and also to insert notes on any non spoken audio which is essential to understanding the event. The viewport containing the caption text is available on the same Web page as the live audio content.

## Examples

- An internet radio station provides a viewport on its Web page for its news services. Live news reports, especially emergency reports, are transcribed by a real-time caption service and displayed in the viewport.

- A conferencing or screen-sharing service includes a window with running real-time transcription of the verbal presentation. This is achieved by arranging ahead of time with a remote relay audio-teleconference captioning service. The online web conferencing or screen-sharing service needs to be designed with this possible usage in mind because using a separate window for the live text would be a significant usability barrier.

- A recurring audio conference uses an online hand-raising utility to assist with queuing. In order to facilitate use of this product in conjunction with an on-line relay conference captioning service, the queuing utility is designed to be fully operational in a narrow viewport. For additional enhancement, a website is created to bring up both viewports within a single Web page.

## Resources

Resources are for information purposes only, no endorsement implied.

- Real-time Captioning

  - CaptionCaster

  - Captioned Text (provider for relay conference captioning)

- Google Directory of Closed Caption Service Providers

- Wikipedia entry for CART (variously Computer Assisted Real-time Captioning or Communication Access Real-time Translation)

- Closed Captioning Web

- Communication Access Information Center

- Web conferencing products with integrated support for captioning viewport

  - IDEAL Conference

  - Acrobat Connect

## Related Techniques

- G150: Providing text based alternatives for live audio-only content
- G58: Placing a link to the alternative for time-based media immediately next to the non-text content
- G69: Providing an alternative for time based media

## Tests

### Procedure

1. Check that the Web page contains a viewport associated with the live audio content.

2. Check that the text of the live audio content appears in the viewport with less than 30 seconds delay.

### Expected Results

- All checks above are true.

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