Comparison in sound energy and spatial properties between direct and flanking transmitted floor impact sound in apartment house

Abstract

In apartment houses, floor impact sound is transmitted to several floors above and below, so many conflicts arise in Korea due to the misunderstanding of the location of the noise source. From the point of view of the residents, not only the sound pressure level but also the spatial and temporal characteristics of the transmission path of the impact sound may differ according to the floor where the floor impact sound is generated. In this study, direct and flanking transmitted floor impact were compared in terms of energy and spatial factors. The rubber ball impact sounds transmitted from the upper 1F, upper 2F, and lower 1F in four apartments was recorded and analyzed. As a result of the analysis, there were differences in the spectrum of the impact sound transmitted from each floor, and the maximum difference was shown in the 100 Hz band. Ratio of the energy of the early sound (0~30 ms) to the total sound (2 s) was found that the direct transmitted impact sound was about 0.13~0.22 higher than the flanking transmitted impact sound. In addition, in the case of IACC (Inter-aural cross correlation coefficient) transmitted from each floor, the direct transmitted impact sound was 0.11 to 0.32 higher than the flanking transmitted impact sound. According to the results of the investigation, energy ratio of early sound energy to total energy is expected that the upper floor as floor impact location can be identified if considered together with the sound pressure level.