Online synchronous sessions are live, interactive learning sessions delivered in real time using a video conferencing platform such as Blackboard Collaborate or MS Teams. Online Captions are the text equivalent of a video’s dialogue and other audio information needed to understand a video’s content. These text descriptions are displayed within the media player and are synchronized with the audio track.  

Captions for Video

Captions provide accessibility for those who are deaf and hard-of-hearing, without them it would be impossible for those who require accommodation to get the full context of your video. Captions are also used by persons who process written information better than audio, non-native language speakers, and those in an environment not conducive to listening to your video. For example, spaces with noisy backgrounds or places where being quiet is expected.

Closed Captions

Closed captions involve creating a separate text document that is added to your video player which then displays captioned text during playback. Viewers are given the choice of toggling closed captions on or off from the video player. This type of caption has the added option of being downloaded separately from your video, making it a more versatile option for viewers. See Fig. 1 below for an example of the closed caption button titled “CC” and the corresponding captions appearing in the video. Closed captions are commonly found on YouTube videos or most TV programming.

YouTube video with closed captions enabled and captions appearing on the video during playback.
Figure 1: YouTube video with closed captions enabled and captions appearing on the video during playback.

Open Captions

Open captions look similar to and display the same information as closed captions, however without the option to be turned off. These captions are embedded onto your video itself and appears during any playback. You may have come across open captions while watching foreign language films. 

Automatic Captions 

Automatic captions are generated using speech recognition software that predict what words are being spoken in your video. Web services like YouTube and Microsoft O365 offer automatic captioning either freely to the public, or through an institutional log-in. Automatic captioning can often be completed in the time it takes to watch a video from start to finish, which makes these services a timely option. However, the accuracy of the automatic captioning is never 100% and requires editing before releasing to viewers.

Live Captions 

Live captioning is an important feature for ensuring that your live video streams are accessible to those who are deaf or hard-of-hearing. Live captioning relies on a skilled individual who listens to your live broadcast and, in real time, delivers reproduced text that instantaneously appears on your live video stream. 

Summary/Key Takeaways

Providing captions for video content is an important responsibility for anyone producing content that is meant for public viewing. When creating accessible video consider which online hosting service may offer inexpensive and efficient automatic captions. For live events, or when automatic captions do not suffice, be sure to budget time and resources for professional captioning services.  

Additional Resources

Ryerson’s Captioning and description page offers great multimedia guides and resources to understanding various captioning options. This resource also includes suggested Canadian vendors who provide audio/video captioning services. 

Visit Ryerson's Captioning and Description Page


  • Photo by tolgart via Getty Images. Used with permission.


(WAI) Web Content Accessibility Guidelines (WCAG) 2.0., (2022, February 21). Video captions. Web Accessibility Initiative (WAI). Retrieved March 4, 2022, from  

(WAI) Web Content Accessibility Guidelines (WCAG) 2.0., (2022, February 21). Media Players. Web Accessibility Initiative (WAI). Retrieved March 4, 2022, from 

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