Evaluating low frequency impact insulation of assemblies using the rubber ball and the tapping machine

The heavy/soft impact source or rubber ball, defined in ISO 10140 and 16283, is used primarily in Japan and Korea to evaluate low-frequency impact insulation. Low frequency impact noise insulation is also measured with the tapping machine using ratings such as LIR and LIIC per ASTM E3207, or weighted impact sound level ratings with spectrum adaptation terms per ISO 717-2. Development of classifications for single number ratings using the rubber ball is an area of current interest. The authors previously presented (InterNoise 2024) laboratory data of impact insulation with both sources demonstrating some characteristic relationships between these sources. The analysis is extended to single number ratings for both sources, and the effect of source and rating on rank ordering and evaluation of the assemblies is investigated. Comparative data from field testing is also presented.