HDTV Audio Problems

Hello, I have a Panasonic 37" Plasma. Recently my television has started to pop (sound) and then all HD channels go to static (audio). The picture is fantastic, however no audio just static, the static will stay consistant even while changing between HD or digital channels. I had a repair tech out and was told that is was my antenna, I needed a stronger one. I purchased a stronger antenna and still I am having the same issue. Some days the audio works, but mostly it just goes to static. My signal strength will show anywhere from 90 to 96%, which I have verified both when I'm getting the static and not. Any ideas?