If you have an audio or video clip in PowerPoint that you want to reuse elsewhere, you can do so by saving the clip as a separate media file (.mp4 or .m4a).
On macOS, this feature is only available to Office 365 subscribers. It's available beginning with version 16.24.
Right-click (or Control-click on macOS) the audio icon or video, and click Save Media as.
Tip: Ensure your disk has enough space to save the media file, otherwise you'll have to free up space and try again.
In the Save Media as dialog box, choose a folder and also enter a name for the media file.
If the Save Media as option doesn't appear on the menu, then you have an older version of PowerPoint that doesn't support this feature.
Install updates for PowerPoint 2013 to use this feature
If you're using PowerPoint 2013, make sure you have the necessary updates to it installed so that you can save a media file.
Check the following:
Install 15.0.4641.1001 or later for the Click-to-run version.
Once you have installed the correct updates, you can save the media file.