"Back 30 seconds" Navi Button?

Is there a way to create a button to appear on slides that allows the student to go back 30 seconds?  In case they're taking notes, and missed something?

I realize you can enable a progress bar to be dragged, but that also allows the user to go FORWARD, too (skipping material).

I have a button that takes you back to the beginning of the slide, but I'd like it to be a 30-second interval (in the event someone doesn't want to re-watch an ENTIRE slide again).

I couldn't find anything previously within the community. I apologize if this is "old news."

Thanks!!

Ed