Investigation of an alternative force input method for impact sound rating

Impact testing has been in use since 1927 for acoustic testing of floor ceiling assemblies. The process used in the United States is defined in the ASTM E1007 standard. This testing method produces an Impact Sound Rating (ISR) which is a measure of the impact sound isolation between an upper and lower room and is used in industry for assessment and comparison of constructions. A standard tapping machine is used to generate an input force. The intent is to deliver a consistent input across all floors; however, the actual input force is dependent on the impedance of the impact device and floor. A soft floor may have a significantly different force than a hard floor. This variance is not accounted for when computing the ISR, resulting in less meaningful test results. This paper investigates an alternative method of impact force generation though the creation of a machine purpose built to measure the input force on any type of floor ceiling assembly. Measurement of the input force would allow for FRF calculations which may be a more informative method of sound isolation evaluation.