Videos often rely on spoken words and sounds to convey information. For people who are deaf or hard of hearing, sign language interpretation ensures they can fully understand the audio content in those videos.
A sign language interpreter translates spoken language into visual gestures, expressions, and movements that convey tone, emotion, and meaning. This provides a richer and more natural way to experience multimedia content beyond written captions.
WCAG Success Criterion
1.2.6 Sign Language (Prerecorded) – Level AAA
All prerecorded audio content in synchronised media must have a sign language interpretation available.
Key points:
- The interpreter should be clearly visible and synchronised with the speaker’s audio.
- The interpretation can be presented as a picture-in-picture overlay or a separate video track.
- This ensures equal access for people who use sign language as their primary means of communication.
Example 1
A company holds a major announcement for all employees. During the live event, a sign language interpreter stands beside the speaker for attendees in the room.
When the recording is posted online, the same interpreter appears in a small video window in the corner of the screen, signing everything that was said.
Example 2
A university records a professor’s lecture on a science experiment. Later, a sign language interpreter records a synchronised translation of the lecture.
When published on the university website, viewers can see both the professor and the interpreter together on screen.
Why This Matters
Captions provide written words but cannot always capture tone, rhythm, or emotional context.
For many deaf people, sign language is their first and most fluent language, while written language is a second one.
Sign language interpretation allows them to absorb meaning more quickly and naturally.
It makes complex spoken content like lectures, discussions, and emotional expressions accessible in the same expressive way it is conveyed to hearing audiences.
When You Should Use It
You should include sign language interpretation when:
- Your prerecorded video includes speech or dialogue that conveys important information.
- The content is educational, instructional, or official, such as announcements, lessons, or training sessions.
- You want to provide full accessibility for viewers who are deaf or hard of hearing and prefer sign language over captions.
How to Add Sign Language Interpretation
There are several ways to include sign language interpretation in videos:
- Embed an interpreter in the video
Record a sign language interpreter and position the video overlay (for example, in a corner of the screen). - Provide a separate synchronised version
Offer an alternate version of the video that includes the interpreter video synchronised with the main presentation. - Use player options
Some accessible media players allow users to toggle sign language interpretation on or off as an additional track. - Ensure clarity and visibility
The interpreter window must remain large enough, well-lit, and unobstructed throughout the video.
Common Mistakes
- Interpreter not visible or too small
Users cannot clearly see gestures or facial expressions. - Out-of-sync interpretation
The interpreter’s signing does not match the timing of the spoken dialogue. - No interpretation for key sections
Only part of the content is covered, leaving critical information inaccessible.
Good Practices
When adding sign language interpretation:
- Use qualified interpreters fluent in the sign language of your target audience.
- Maintain consistent lighting and framing for visibility.
- Keep the interpreter video synchronised with the spoken audio.
- Allow viewers to choose between captioning and sign language if possible.
Ask yourself:
- Does this video contain important spoken information?
- Will someone who relies on sign language fully understand it?
- Is the interpretation clear, synchronised, and easy to follow?
Wrapping Up
Sign language interpretation makes videos inclusive for people who are deaf or hard of hearing.
It delivers emotion, emphasis, and meaning that written captions alone cannot express.
By adding a synchronised sign language interpreter to prerecorded videos, you meet WCAG Success Criterion 1.2.6 Sign Language (Prerecorded) and provide equitable access for all viewers.
Without interpretation → “I can read the captions but miss the expression and flow.”
With interpretation → “I understand everything naturally through my first language.”
Adding sign language interpretation isn’t just about compliance; it’s about communication, inclusion, and respect for diverse ways of understanding information.
