Is there a way to mute all voice chat on the Xbox 360?

I don't really care about the voice chat, and I don't use it at all, I don't even have the headset. But I'm still forced to listen to all these kids with really annoying high voices, saying stupid stuff over my speakers. With some games I can mute people but that is only a temporary solution. Looking for some sort of universal setting for the console to turn all voice chat off. I cant find it, if it exsists.