Very very important question

To sum up my story, I've been working on a bunch of projects that involve videos. Up until recently there have been no issues, until today when I get on my computer, I find that half of my videos are corrupted. Well kinda, because the video itself is fine, the audio part on the other hand, is a wreak. I've tried multiple 'repair' software but nothing seems to work. Can anyone provide insight or give me ideas on something to do? It's nothing to do with space, because I have almost 400 gigs free still. But overall, we're talking about 100 gigs of videos corrupted...

Was the audio recorded at the same time as the video? Or is it post production?

It was recorded at the same time, in frapps.