Quoted from nate1981s:like markmon said above. These panels are really for high frequency absorption to stop reflections. Also, if you do not treat the entire wall and also add deadening board it probably will make no or little difference. An example is like having a slight cracked window on a very cold night. Huge heat loss from just a little crack.
Yeah, *if* the sound is getting through to the point that it's a problem, then damping one wall doesn't have a great chance of resolving it. The sound vibration just finds another path.