Low frequency impact noise floors insulation by source of impact noise

Abstract The objective of this study was to evaluate the sound pressure level generated by different types of impact noise sources in buildings at frequencies between 80 - 400 Hz using different floor combinations and resilient materials for the flooring system. Measurements were conducted using two sources of impact noise, a tapping machine modified according to international standards and a non-standard 5 kg punching bag. Three types of floor (bare slab, ceramic flooring and laminated flooring) and two resilient materials (glass wool and EVA) were used. Impact noise sources were placed in four different positions. Data were collected at 16 microphone positions in the receiving room, and analyses were performed for 4, 12 and 16 microphone positions. It was concluded that the impact sound pressure level (LnT) present in the receiving room under excitation with the modified tapping machine varies according to the type of resilient material used, while for the non-standard impact noise source the results in terms of maximum impact sound pressure level (Li, max) vary largely according to the different types of flooring used, especially in the 80 Hz band. In this case, the resilient material also influences the sound pressure levels, but not as much as it influences the pressure levels of the standard source.

摘要 本研究旨在评估采用不同楼板组合及楼板系统弹性材料时，建筑内不同类型撞击噪声源在80~400Hz频段下产生的声压级。本次测试采用两类撞击噪声源：一类为符合国际标准修改的撞击机，另一类为非标准5kg撞击沙袋。实验涵盖三类楼板（裸楼板、陶瓷地砖楼面与层压复合地板）及两类弹性材料（玻璃棉与乙烯-醋酸乙烯酯共聚物（EVA））。撞击噪声源被设置于四个不同位置。接收室内共布设16个传声器测点，后续分析分别选取4、12及16个测点开展。研究结论显示：采用改性撞击机激发时，接收室内的撞击声压级（LnT）会随所用弹性材料类型发生变化；而对于非标准撞击噪声源，其最大撞击声压级（Li,max）的结果主要受不同楼板类型的影响，尤其在80Hz频段内。在此场景下，弹性材料虽也会对声压级产生影响，但相较于其对标准声源声压级的影响程度，作用相对有限。