Evaluating Field Measurements of Impact Sound

Analyzing data from an earlier investigation revealed uncertainties concerning data evaluation. Therefore, data points comprising 1/3-octave impact sound data and interview data from the earlier investigation are partly replaced by new data points. The data removed pertain to horizontal measurements. The investigation is then completed with data for 10 new housing units pertaining to vertical impact sound measurements. Including the new floor structures, a total number of 22 vertical data points are included. It was found that the current international standard method is unsatisfactory, and that the single-number value proposed in the earlier investigation suffers from shortcomings: when analyzing the new data sample, the correlation coefficient fell from 87% to 83%. The best choice proved to be a reference curve with a steep positive slope of 5.5 dB/octave between 50-100 Hz and the curve becomes a straight line. This reference curve resulted in a correlation coefficient again equal to 87%.