요약2 |
Floor impact sound is one of the most annoying noise sources in multi-story residential building. People usually do not wear shoes in a floor-heated house, in such cases children's running, jumping and adult walking generate low frequency impact sound. In order to simulate and test low frequency impact sound in multi-story residential buildings, heavy/soft impact source (rubber all) was standardized in ISO 10140-3, 5 and ISO 16283-2. However there is no single number quantity (SNQ) to evaluate rubber ball impact sound. For the proposition of SNQ on rubber ball impact sound several subject tests were conducted. The most of subjective test focused on level variation. In this study, frequency component of rubber ball and real impact sound, which were recorded in typical Korean residential building, were varied and presented to the subjects using headphone. Subjective loudness were evaluated and compared with several SNQ such as A-weighted maximum impact sound pressure level (LA,F,Max), arithmetic mean level (LiF,avg,Max) and inverse A-weighted maximum impact sound pressure level (LiFmax,AW). It was found that LiF,avg,Max and LA,F,Max show higher relationship than other SNQs. |