Closed captions which copy screen text - are they necessary?

Jun 23, 2020


I seem to keep going down this rabbit hole with my friend Google, but not getting anywhere concrete.  The course that I'm working on has all the text content on the slide, which is 99% the same as the TTS audio, and also the same as what's in the Notes tab, which is available to the learner.

We're trying to figure out if we still need closed captioning for the course because it's just another copy of visual text content that already exists in two places.  There are very rare instances where the audio doesn't perfectly match what's on the slide and the differences are very minor.  Has anyone gone down this path before and figured out what was actually required?

We're considering having an accessibility consultant come in to give us advice, but it would be a while before that happens.  The closed captioning is so time consuming that it would be nice to know if it wasn't required.  If anyone has any resources to share where they've found a documented answer, I would greatly appreciate it!

For context, I'm in Ontario (so looking to follow AODA) but I would be open to ANY information that would help my team make a decision on this and feel confident about it.


2 Replies
Sam Hill

Hi Lindsay, I would argue that the text on screen is acting as closed captions. Because the audio does not need to be hear at a particular time in sync with an event, the slide text is adequate and most likely a better experience as it can be read at the users own pace, much like an audio transcript.

Just make sure that your slide text can be accessed by screen readers.

I think closed captions are redundant in this instance as you are already providing a text equivalent of the audio track.

The only thing to look out for though is, can a user read the text content quicker than the audio track is played? Once they have finished reading, do they then have to wait for the audio track to complete in order for a Next button to be enabled, or for content to appear on the slide? This can create periods of silence for some users where they have finished reading the content on page, and are waiting for an event (that they are unaware of) to happen on the slide.

Marianick Pichon

Hi Lindsay,

Thanks for your post, it is the only one I found about this topic!

Here's what is stated in the Web Content Accessibility Guidelines from W3:
"1.2.2 Captions (Prerecorded)
Understanding Captions (Prerecorded)|How to Meet Captions (Prerecorded)

Captions are provided for all prerecorded audio content in synchronized media, except when the media is a media alternative for text and is clearly labelled as such."

In your case (and mine lol), the audio IS a media alternative for the text that's on the slide, right? So the WCAG say: no need for captions.