What Exactly Does IIC, INR and STC Mean?
Sound rating methods have been established by the Federal Housing Administration (now HUD) and the National Bureau of Standards. These sound rating methods are recognized by building construction regulatory bodies and agencies. ASTM and ISO acoustical testing methods are used as the criteria to determine acceptable sound transmission standards. Impact Insulation Class (IIC) Impact sound originates when one body strikes another, such as in the case of footsteps, hammering, and objects falling. Impact sound travels through the structure with little loss of energy if the structure is continuous and rigid. Transmission of impact sound can be controlled by isolation. IIC ratings are greatly improved by the introduction of QuietCORK . The higher the IIC number the better the impact insulation. Impact Noise Rating (INR) The earliest single-number rating system was called the Impact Noise Rating (INR). This has since been replaced by Impact Insulation Class (IIC) as described above. IIC values
