MLV or Mass Loaded Vinyl is a sound barrier blocking material known
as a Limp Mass Barrier.” The material is comprised of two principle ingredients: vinylto
give the MLV flexibility (the so called limpness) and, a naturally
occurring, high mass element. Often Barium Sulfate is used due to
its unique properties it is non-toxic and has a high relative
density. This latter attribute of high density is what makes Mass
Loaded Vinyl so effective in blocking sound.