But, can it be more than just “insulation”? Yes, in fact certain types of materials are excellent at reducing the amount of sound transfer through them. Open Cell spray foam is an example of insulation that offers great reduction in sound transfer.
Other insulation materials are considered “air barrier” materials that allow such low amounts of air transfer – they are considered air barrier materials. Closed cell spray foam is an example of insulation material that prevents air from moving through it.
While there are many different material types of insulation, there is usually one type that is best suited for a particular installation. Even blown-in loose fill materials have different properties with different “R-values” and effectiveness.