Problems with sound in SSFIV:AE and MVC3

hey guys

So I got a new TV yesterday (Toshiba), and when I play street fighter, the volume seems to decrease itself (when I attack or use special moves), and after a second or two, the volume increases again.

I thought maybe it was a problem with dynamic range, but that feature is off on my tv, and the problem is still occuring. The same thing happens with MVC3 as well.

Any ideas as to what the problem could be? Thanks in advance!