Association between hearing threshold and low-frequency walking sounds on concrete floors

The sufficient frequency range to be measured for the rating of impact sound insulation of floors has been a relevant research question since the 1960’s when the lower limit of the measured frequency range was set at 100 Hz. It has been long recognized that walking sounds at frequencies lower than 100 Hz might have a significant effect on the experienced impact sound insulation of floors. Recently, it has been suggested that the frequency range to be measured for the rating of impact sound insulation should be enlarged down to 20 Hz. This suggestion is based on studies concerning wooden buildings. It is not known whether audible low-frequency walking sounds are generated by walking on
concrete floors. The purpose of this preliminary study was to produce sound spectra of several living impact sound sources, and to compare them with hearing thresholds. The spectra of different sound sources were measured in a laboratory. The results show that low-frequency living sound spectra exceeding the hearing threshold exist only at 40 Hz and occasionally at 31,5 Hz frequency band in the case of walking with socks on concrete floors.