What's wrong with my TV

So over the last few days most of the channels on my TV have a perfect picture but the only sound I get is fuzz. It was working fine and then just stopped. I tried unhooking & re-hooking the cable but it didn't do anything. I don't have cable so I can't call my cable provider about the problem so does anyone know who I would call? My mom's TV upstairs works fine. Last night we watched Heroes and fortunately NBC worked fine until the news came on. Right when the news started we couldn't hear the anchors talking, what we heard was someone translating the broadcast into Spanish. I went upstairs to my moms to see if it was just a problem KSL was having but her TV was working fine. Any ideas on how I can fix this problem?