Tvad, Why not put some flesh on your question?
What is the noise source?
What kind of component?
How do you percieve using the materiel? Just as a pad between the component and the shelf. To enclose the component? To line a cabinet/box? etc.
BTW, if it is transformer hum, and the component sits of a shelf in the open, I have gotten little relief from putting sound absorbent materiel between the component and the shelf. I've used heavy dense sound aborbing foam as well as sorbothane. I always got the best benefit from damping the transformer itself.
FWIW.