Sound Reducing, can it be done>?

I had to mount a flat screen to the only wall that would let me, and in the next room is my one year old daughter. If you turn it up to loud or even play the XBox, you can hear some of the sound. Is there any kind of way I can reduce that sound for my daughter. I was thinking of throwing some installtion between the sheetrock from the attic. Or is there a better way of going about this?