Presenter is part of Captivate, which... to my knowledge... has never been available for Macs. Believe me, I'd love to have Captivate for a Mac so I wouldn't have to use my Windows 8 PC to make Presenter content.
I digress though. Does your Flash Player work elsewhere? I mean, do you have video and audio on websites like YouTube?
If you do, then the problem ISN'T with Flash Player but something in the Presenter content.
Yes, no problem with You Tube. Other students with the same configurations of OS, Safari, Adobe have audio. I must be missing something...