It is common for people who don’t have knowledge of the science of acoustics and sound to get confused about what is meant by sound proofing and sound absorption. The two are actually very different and have very different purposes so it is important get basic understand of both before deciding what’s required.
So let’s start with sound insulation. Sound insulation is all about blocking sound waves and preventing them travelling from one room in a building to another. If for example you imagine a fish tank, the water in that fish tank is kept inside by some strong glass.
Now if that same fish tank was made of cardboard, then water would soon start leaking through. Sound behaves in a similar way to water so the materials you choose for sound proofing should be aimed at preventing sound coming through altogether.
Sound absorption material on the other hand converts sound into friction. It also tends to be lighter in weight and has properties that act to prevent sound reverberating around a room. If a room is fitted with sound absorbent material, people in the room will be able to hear what other people in that room are saying better. In other words sound quality will be better.