Note that captions are only created while PowerPoint is running. Should you be using this facility in a teaching session, and switch to providing another type of document on-screen, the captioning will be ended.
PowerPoint can transcribe your words as you present and display them on-screen as captions in the same language you are speaking. There are also position, size, color, and other appearance options for the captions and subtitles to accommodate different environments and audience needs.
For best results, we highly recommend using a headset microphone connected to the device running PowerPoint. Also, the feature requires a reliable internet connection throughout your presentation. Requires Windows 10, and PowerPoint for Microsoft 365 version. The feature isn't supported if you're using an earlier version of Windows.