3.7 Multimedia (Audio & Video)

To ensure full accessibility for all viewers, important visual elements in your video must be included in the audio. One effective method to achieve this is called audio description: a separate audio track narrating visuals and actions. Audio description is usually indicated with an AD or D))) logo or icon. Audio description requires a separate script and recorded audio track, and some video players do not support multiple audio tracks.

As an alternative, integrated description may be a simpler solution. An integrated description is a way to describe visuals aloud as part of the video’s natural flow. This accessibility practice benefits not only blind and visually impaired viewers but also all viewers, who will be better able to follow along, particularly if a video includes demonstrations or instructions. Integrated description may help reduce audience members’ cognitive load because it reduces the need to split their attention between visuals and audio.

To include integrated descriptions in your script, consider the following best practices:

1. Avoid sensory-only instructions that rely on sight or colour.
2. Describe what is on screen in specific terms: refer to important images, charts, logos, etc., and write descriptions and practice reading them to maintain the flow of your presentation:
   • Mention slide numbers, figure labels, question numbers, etc.
   • Refer to specific named elements like menus, links, buttons, page features like headings, regions (sidebar, navigation menu, footer, etc.), and major waypoints like breadcrumb navigation or pagination.
   • Describe actions like “open menu,” “click button,” “select checkbox,” etc.
   • Avoid vague references like “here” or “there” as most users may not know where you are referring to.
   • Use relative positions including above, below, left, right, top right, etc., as readers and assistive technology typically read in a Z pattern starting at the top left.
   • Provide summaries of charts, lists, or other data groups; Include relevant information about the relationship and hierarchy between information.

Remember that you are the expert in the content you are presenting. You know why information is included and what is important. Consider asking someone to listen to your audio presentation without seeing the visuals and ask what parts were hard to follow or confusing.

Try to use simple language when possible. Explain complex terms, jargon, abbreviations, and acronyms. Write for the intended audience.

When recording narration or voiceover:

• Ensure there is no background noise.
• Use a dedicated microphone (not the microphone built-in to a laptop, for example) when possible.

When recording with a camera, remember to record:

• In at least 720p resolution.
• With a neutral, consistent background.
• With adequate lighting.

When recording your screen:

• Remove clutter.
• Silence notifications.
• Record only the main content.

If screencasting or filming a whiteboard, remember to:

• Avoid using colour alone to convey meaning.
• Use sufficient colour contrast.

• Avoid content that flashes more than 3 times per second. Flashing content can cause seizures.
• If flashing content is essential, provide a warning at the start of the video.

An accessible video player supports closed captions transcripts, is keyboard accessible, and does not autoplay. Support for an additional audio description track is a bonus, but not required.

Captions are the text of the audio in a video, synchronized with the video content. To create captions:

• Use automatic captioning tools to develop a draft.
• Edit automatically generated captions, ensuring names and terminology are correct.
  • Include relevant sound effects, music, and other non-speech audio elements.
  • Identify speakers if not visually obvious.
• Sync caption timing with audio.

Closed captions can be toggled on and off by each viewer. Open captions are part of the video file and cannot be toggled on and off. Prefer closed captions except for foreign language subtitling.

A transcript is a text version of multimedia content. To make a transcript:

• Copy captions to a blank document, remove the timestamps, and format into paragraphs.
• Transcripts can include additional information such as action, setting, or persons present in the video.
  • Integrated description will already include this information and eliminate the additional work of adding descriptions to the transcript.
• The transcript can be a useful place to share links mentioned in the video.

Source: Fraser & McKnight, 2023.