Evaluation of field impact sound pressure levels as a function of tapping machine location

Field impact sound insulation in the United States is typically quantified in terms of field impact insulation class, which is defined in ASTM E1007. This standard requires averaging the receiving room impact sound pressure levels (ISPL) generated by the tapping machine in four defined positions. In a previous paper [LoVerde and Dong, J. Acoust. Soc. Am. 121, 3113 (2007)] the authors analyzed several hundred field tests to determine effects of reducing the number of tapping machine positions on the FIIC rating. In this paper the analysis is extended to look at the detailed effects on the third-octave band ISPL, which may impact design decisions more than the overall FIIC rating. The effect of reducing the number of positions as a function of assembly construction is also examined.