The audio dropouts seem to be king of random, both during commercials and the program. They were happening during the NASCAR race and 24 yesterday, but have been happening over the past 2 weeks or so. I also noticed it Saturday during the marathon Mets-Cardinals baseball game. I usually watch OTA to avoid the BRRRPS, but I have been watching with D* lately. They seem to take a second or two, and seem to be random, but the sound is repeatable. The sound goes out for about 1-1.5 seconds, then it seems to try to come back, then disappears again for about another 0.5 second.
I once in a while watch 2 1/2 men at 6 and 6:30 for local programming, and honestly, I haven't noticed them during this. Lots of times I have this on as background noise though, and don't pay close attention to it. I will try to pay better attention more the next time I watch.