Digital Accessibility

According to U.S. government figures, one in eight people has some level of functional hearing limitation, and this number is expected to rise as the population ages. Beyond individuals with disabilities, captions also benefit people who only partially understand the language presented. Additionally, captions are helpful in noisy environments like airports, quiet settings like libraries, and for supporting multimodal learning.

Appropriate use

Captions on audio/video content: You can use tools like Kaltura Media Space as a starting point for creating automated captions. For people with disabilities, automated tools may not be enough to provide fully accessible versions. You will want to review the captions to ensure that they are accurate.

Transcripts as alternative media: Transcripts, unlike captions, are not always properly synchronized with audio content. For items like podcasts, TED Talks, interviews, or other mediums where there aren’t a lot of additional movement and sounds that need to be referenced, a transcript could be an acceptable media alternative.

Captions in third-party sites: If you’re using a third-party tool like YouTube, you can often use the filter option after searching to show only videos with captions.

On YouTube, after performing a search, click the filter button on the right and select “Subtitles/CC” to show only videos with captions. Please note that you’ll still need to verify the accuracy of these captions. You can then import them into Kaltura to make any necessary edits.

Captioning guidelines: The Described and Captioned Media Program (DCMP) has created standards for formatting and displaying captions. In addition, the W3C Web accessibility Initiative (WAI) has technical standards for WebVTT (closed caption formatted files).

Below are some of the highlights for you to review:

• Limit lines to 32 characters or less, including spaces.
• It is preferred that there are no more than 1-2 lines of text per screen.
• Use sentence case rather than all caps.
• Use a readable font of average thickness. Use of white characters is preferred, with medium weighted sans serif font.
• Text should be centered on the screen and left-aligned.
• Color contrast should be sufficient to stand out against the background (but not visually disruptive).
• Captions should a have a minimum duration of 40 frames (~1.5 seconds) and a maximum duration of 6 seconds. Background music notation is an exception to this guideline.

How to test for compliance

You should always review the captions to ensure that they are accurate, which includes:

• Accuracy: Correct grammar and punctuation are important to convey intended meaning (e.g., “Let’s eat, Grandma” vs. “Let’s eat Grandma”).
• Consistency: Uniformity in style and presentation of all captioning features is crucial for viewer understanding.
• Clarity: A complete textual representation of the audio, including speaker identification and non-speech information, provides clarity.
• Readability: Captions need to be displayed for long enough to be read completely. They need to be synchronized with the audio, and they must neither obscure nor be obscured by the visual content.
• Equality: Equal access requires that the meaning and the intention of the material are preserved as much as possible.

Common mistakes

Not checking for accuracy: In many cases, unusual words like “Rutgers,” may appear as “Rukers.” Be sure you are reviewing the captions prior to publishing your video.

Other resources

• Described and Caption Media Program
• W3C WAI WebVTT Technical Standards

WCAG standards

• A 1.2.1 Audio-only and Video-only (Prerecorded): For prerecorded audio-only and prerecorded video-only media, the following are true:
  • Prerecorded audio-only: An alternative for time-based media [transcript] is provided that presents equivalent information for prerecorded audio-only content.
  • Prerecorded video-only: Either an alternative for time-based media [descriptive transcript] or an audio track [of description] is provided that presents equivalent information for prerecorded video-only content.
  • AAA 1.2.8 Media Alternative (Prerecorded): An alternative for time-based media [transcript] is provided for all prerecorded synchronized media and for all prerecorded video-only media.
  • AAA 1.2.9 Audio-only (Live): An alternative for time-based media [live stream text or transcript] that presents equivalent information for live audio-only content is provided.