I agree with treazzure007. My thirteen year old son is, and has always been this way. Sometimes we have little contests to see who can be the quietest or give a little prize if he (and his siblings) can go the rest of the way to our destination (usually just a few blocks) without talking. It teaches the kids to control themselves and gives us a tiny bit of quiet.
Dont bother trying to get him to hush. Children are so adorable at this stage. My son is the biggest chatter box of all time.
The only thing that we have ever had trouble with is his talkativeness. Teach your child that there is a time and place for everything. Talking and playing are for outdoor/playtime/freetime at school. Teach him that school is a very important place for learning and the teachers are appointed authority figures while he's there so they have to be respected too. Just keep reiterating this and use punishment when the rules are broken. Good luck