Background static when watching movies

I seem to be having this issue with newer movies, like The Grey and The Help, where, at parts where there is no background noise and just the people speaking, there is static that is very apparent in between when the actors speak. All the movies i have are encoded in Handbrake with the AC3 passthru setting, and i'm playing them through our TV with XBMC, though we don't have a surround sound set, just the stereo speakers which are built into the TV. Has anyone experienced this static phenomenon before?