An indirect method for the measurement of impact sound insulation
* Presenting author
This paper describes a way of measuring impact sound insulation for heavy structures without using the standard tapping machine. Instead, another source of known contact force – e.g. an impact hammer or electrodynamic shaker – is connected to the building element under test. The sound pressure level is measured in the receiving room and then corrected from the difference in force level between the standard tapping machine and the substitution source to obtain the impact sound pressure level. An application of this indirect method is the laboratory determination of the impact sound performance of walls, which can be used as an input for prediction of impact noise of isolated heavy stairs as well as of structure-borne noise from service equipment in situ; the standard tapping machine is indeed not suitable for exciting vertical building elements. In this paper, the indirect method is described, then applied to a floor element and the results are compared to the impact sound pressure level directly determined using the standard tapping machine on the same floor. Several measurements are performed using different numbers of source and microphone positions. The corresponding results are presented and discussed.