Subjective and Objective Rating of Impact Sound Insulation of a Concrete Floor with Various Coverings

The aim of the study was to determine the associations between subjective rating of impact sounds directed to concrete floors and various single-number quantities (SNQ) of impact sound insulation. A psychoacoustic experiment was participated by 55 subjects in order to rate subjectively 44 sounds which were recordings of five actual impact sound sources directed to nine floor types. Eight objective SNQs were calculated. The squared Pearson correlation coefficients R ² was determined between the objective SNQs and subjective annoyance or loudness. Statistically significant correlation between the SNQs and subjective ratings was detected for three sound types out of five. Of the SNQs presented in ISO 717-2, the best indicators of subjective loudness and annoyance regarding walking with hard-heeled and soft-heeled shoes and chair moving were L'_n,w + C _I and L'_n,w + C _{I , 50–2500} followed by SNQs developed by Fasold, Gerretsen and Bodlund. L'_n,w and the SNQ developed by Hagberg correlated weaker with the subjective loudness and annoyance of the mentioned three sound types. The subjective ratings of walking with socks and superball bouncing were weakly or not at all correlated with the SNQs. As walking with socks is probably the most common impact sound type in some countries including the Nordic countries, the present SNQs do not cover all important sound types occurring in dwellings. Thus, there is a need for the development of new SNQs which would correlate better with general sound types.