Did you know that PowerPoint offers free subtitles on presentation mode? This is a great work-around if you want subtitles (English-English) or (French-French). Here is a link to an article by Microsoft which will guide you on how to enable this free feature. Click Here
The following YouTube video also demonstrates how to enable the closed captioning but please use the same language for “Spoken Language” and for “Subtitle Language” as the language translation is not accurate.