We had a shoot with a new C200 and when we got into editorial, at one point the interview audio (XLR sennheiser mic) starts to have a lot of flange. It's the same sound that you produce when you have heavy noise reduction applied. I describe as "swishy".
It wasn't there at the beginning of the interview and seems to be introduced with a small change in volume (I think the camera operator dropped the volume just a touch).
We were shooting AAC compressed audio, but we've done that a lot before with no issues with the C200.
Any ideas? Not sure we can fix it, I'm just wanting to figure out why it happened and see if anyone has had a similar issue?