Currently live time-based media does not require captioning in law, but the regulations are moving in this direction to match EU Directive 2016/2102 where live time-based media that are kept online or republished after the live broadcast should be considered as pre-recorded time-based media without undue delay from the date of the initial broadcast or republishing of the time-based media, that necessary period of time should in principle be no longer than 14 days.
PowerPoint for Microsoft 365 can transcribe your words as you present and display them on-screen as captions in the same language you are speaking, or as subtitles translated to another language. This can help accommodate individuals in the audience who may be deaf or hard of hearing, or more familiar with another language, respectively.
There are also position, size, colour, 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.