Noise Reduction is Achieved in Two Ways With Cellulose
The first is that cellulose completely fills cavities leaving few air pockets for sound to travel in.
The second is the cellulose materials ability to trap air.
The significant difference between noise reduction with cellulose and fiberglass is its density.
Density
Cellulose is approximately three times denser then fiberglass. This helps deaden the sound through walls and between floor levels.
Several installation options allow walls to have a Sound Transmission Class (STC) of 50 or greater. As a comparison, walls with fiberglass batts have an STC of 36-39, depending on stud and screw spacing.
Ecocel cellulose performs up to 7dB better acoustically compared with conventional fibre mats.
There is a RW45 [ acoustic rock wool ] product which as the name says goes in at density of 45kg/m3.
Ecocel cellulose can achieve densities above 70kg/m3 when required for sound insulation.
