Havelock Wool is not only a great insulator but it excels at absorbing sound.
A Noise Reduction Coefficient (NRC) is a rating for how much sound a material absorbs. Like a sponge absorbs water, insulation absorbs sound and the NRC tells us just how much sound gets soaked up. The higher the NRC rating, the better the sound absorption. So a material with an NRC of 1 absorbs 100% of sound. In the insulation world, NRC is an important factor because along with regulating temperature, insulation should also keep your living space quiet.
Havelock Wool’s NRC of 90 and 95% (batts and loose-fill, respectively) beats most other insulation mediums. To be fair, there are some products with a slightly higher NRC but those tend to be designed specifically for sound absorption. As such, they fall short on other important metrics like R-Value…. not to mention moisture management, air filtration, and sustainability.