Predicting Sound Power Response from a Simply Supported Rectangular Panel for Impact Insulation Class (IIC) Test

Impact Insulation Class (IIC) test defined by ASTM is widely used to characterize the response and performance of floor/ceiling assemblies. However, this method suffers from some limitations at low-frequencies. Because of the non-modally dense behavior of the receiving room in the lowest third-octave band, 100 Hz, the room correction lacks repeatability across different laboratories. This results in poor reproducibility of IIC results from lab-to-lab. In this method, we are proposing to use a test panel of known sound power to calibrate the receiving room, foregoing the requirement of a diffuse field. The known sound power of the test panel comes from analytical calculations for simply supported rectangular plates and the prediction is compared with the experimental response measured using an intensity probe.