Animation

Software checkpoint 3.2

Provide accessible alternatives to significant audio and video.

Rationale

Audio content is not accessible to users who are deaf or hard-of-hearing. Video content is not accessible to users who are blind. If the audio and video information are important, they need to be provided in an alternative format which is accessible. Alternatives for audio and video content are also needed by those who have hardware or environmental limitations. For example, the captions on a video can be selected when the audio would be distracting to others in the area.

Section 508 requires that equivalent alternatives for any multimedia presentation be synchronized with the presentation. If the product is to be used by or sold to the U.S. government, for example technical software, the equivalent alternative (such as captions and audio descriptions of the video) must be synchronized with the presentation.

Development techniques

For audio content, use one or more of the following techniques to meet Checkpoint 3.2 from the IBM Software Accessibility Checklist:

Provide a text transcript for the audio. A transcript is a word-for-word textual version of the audio. The user should be given the choice of reading the transcript or listening to the audio, or both. If the product is to be used by or sold to the U.S. government, the transcript must be synchronized with the presentation.
Provide a text description for the audio. A description is longer and more significant than a transcript. The description can be both subjective and artistic, depending on the intentions of the author. If the product is to be used by or sold to the U.S. government, the description must be synchronized with the presentation.
Provide a caption or pop-up text window for short audio information. If the product is to be used by or sold to the U.S. government, it must be be synchronized with the presentation. Captioning is the rendering of speech and other audible information in to written language of the audio. Captions are usually closed which means the captions are encoded or invisible and must be decoded or made visible. Some captions are open and can't be turned off

For video content, use one or more of the following techniques:

Provide a transcript for the video. A transcript is a word-for-word textual or audio version of the video. If the product is to be used by or sold to the U.S. government, the transcript of the audio must be synchronized with the presentation.
Provide a description for the video. A description of a video track is different from a transcript. The description summarizes any visual information, including action, settings, and characters that are necessary to understand the video. The description of the video should be made available in text and audio form. It can be both subjective and artistic, depending on the intentions of the author. If the product is to be used by or sold to the U.S. government, the description must be synchronized with the presentation.

Using Media Access Generator (MAGpie) from WGBH, authors can add captions to three multimedia formats: Apple's QuickTime, the World Wide Web Consortium's Synchronized Multimedia Integration Language (SMIL)and Microsoft's Synchronized Accessible Media Interchange (SAMI) format. MAGpie can also integrate audio descriptions into SMIL presentations. For additional information about media formats, tools and players that enable captions and video descriptions, see the WGBH National Center for Accessible Media.

RealPlayer allows the user to turn on captioning. For more information, visit http://www.real.com/.

The following example illustrates a transcript of speech and other sounds that enable the user to understand the content more clearly:

[phone rings]

Man: Are you going to answer the phone?

[phone rings]

Woman: No, I'm screening my calls.

[answering machine picks up in the background]

The following is an example of a video description file for the sample movie:

[A computer showing text highlighted in a browser window as the text is read aloud by a synthesizer]

Reporter: A screen reader brings the voice of the Internet to blind and visually impaired users

[A man sitting at the computer listens to the synthesized voice. Text is highlighted as it is spoken]

Computer: [synthesized voice of a screen reader] ... A screen reader brings the voice of the the Internet to blind and visually impaired users. [video clip ends]

[video clip ends]

Testing techniques

Test the software to ensure that it complies with accessibility requirements.

Tools

Install the following tools to test this checkpoint:

A screen reader such as JAWS or Window-Eyes will be needed to test accessible alternatives for video. A screen reader is not needed to test accessible alternatives for audio presentations.

Techniques

The following techniques are required to verify this checkpoint:

Action	Result
1. Verify information in the video is also available with a text or audio description of the video. If there is an audio description, listen to the description to see if it matches the video. If there is a text description, listen to the text with a screen reader. Verify the information is accessible to the screen reader and that the description matches the video.	Pass: There is an audio or text description for the video. If there is an audio description, it is equivalent to the video presentation. If there is a text description, it is read by the screen reader and the content is equivalent to the video presentation. If the product will be sold to the US federal government, the audio or text descriptions are synchronized with the video. Fail: There is no audio or text description for the video. There is an audio description, but it is not equivalent to the video presentation. There is a text description, but it cannot be read with a screen reader or the content is not equivalent to the video. The product will be sold to the US federal government and the audio or text descriptions are not synchronized with the video.
2. Verify information in the audio is also available with a text transcript or captions. Read the text transcript or captions. Verify the information is equivalent to the audio.	Pass: There is a text transcript or captions for the video. The content is equivalent to the audio presentation. If the product will be sold to the US federal government, the text transcript or captions are synchronized with the audio. Fail: There are no text transcripts or captions for the audio content. There are transcripts and captions, but they are not equivalent to the audio presentation. The product will be sold to the US federal government and the transcripts and captions are not synchronized with the audio presentation.

Last updated January 24, 2008.

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