- What kind of footage are you using? What did you shoot on? Was audio recorded separately?
- Are you editing on your Mac HDD, or are you using a separate external? Have you experienced any issues with that device? Or your ports?
I know it might seem silly, but just covering all the bases.
Go to Window>Events the next time this happens, and please let us know if anything shows up. Sometimes it will tell you what's happening.
It might have to do with a bug that stops audio from playing. I have it happen every now and then, too. I've read online that it has to do with a bug that should've been repaired by now.
