A great update came out recently where you can turn on automatic Closed Captioning in Google Slides.  All you have to do is to start a presentation and click the Closed Captioning button in the toolbar that pops up in presentation mode.  This feature should be rolled out to all education accounts by now but if you do not see it yet, it should be out very soon.  

This is a great feature if you have any student who has hearing issues or could use some help to understand what you are saying, by seeing what you are saying.  Watch the video below to see how it works and give it a try the next time you are doing some direct instruction using Google Slides.