Audio description

An audio description is additional voice-over (narration or commentary) that explains what is happening on screen.

It is only needed in cases where important information or actions are happening on screen but not clearly described in the audio track.

An audio description fills in missing information for someone who can’t see what’s being played. If videos are created with accessibility in mind, audio descriptions won’t be necessary, if important visual elements of the video are described in the audio track itself.

Example of audio description: Apple accessibility – Sady (with audio description)’ on YouTube.

If your video doesn’t allow you to add a second audio track (it’s currently not an option in YouTube or Vimeo) then you need to make a second version of the video and include the extra information in with the main narration/audio.