This issue seems to be happening when we DVR anything on ABC HD. When we watch the DVR'ed show, the background sound/music/noise is twice as loud as the dialogue and the dialogue always sounds muffled. We are not having any other problems with any other channels. The issue is also occurring on the same channel on the different TVs in our house.
We have called Verizon, who told us to unplug and reset, which we did but it does not help. I read we needed to change the audio output to L-PCM, but it is not possible on our set top box, which is a SYSCO. Please help. So annoyed! We never had these issues with Direct-TV.