I don't think it's your speakers, radio, or anything like that. (If it was, it would affect your whole computer, not just your TB application.)
I've seen similar things like this happen to people several times, and almost everytime, the solution to the problem was simply updating your drivers.

(I'll simplify the "drivers" concept to you through PM. Now, im going to show you ways to fix this problem.)

Click on the start menu.
Click on "Run".
Type in "dxdiag" in the space provided.
Copy what it says there, and paste it here.