Reduction of Floor Impact Noise of Wooden Houses

在木制房屋中，降低木质地板上产生的地板冲击噪声是相当困难的。该项目的目的是在木制房屋中开发由木质板地板和天花板组成的隔音系统。针对不同的噪声源、材料和结构进行了实验。结果表明：（1）A特性声压级总值La与C特性声压级Lc之间存在线性正相关关系;（2）地板冲击噪声的降低水平与地板材料的平面密度呈线性相关关系;（3）敲击噪声中，设置吊顶可降低声压级525 dB，设置浮动地板或声屏障可降低声压级10-35 dB，设置吊顶、浮动地板可降低声压级12-40 dB。4）在轮胎跌落噪声和脚步声中，上述系统的声压级分别降低了2-16 dB和5-25 dB; 5）根据噪声级与振动加速器的关系，确定了地板冲击噪声的辐射因子。这些因子与Beranek方程中的因子符合得令人满意。利用这些因子可以预测噪声声压级。

In a wooden house, it is quite difficult to reduce the floor impact noise generated on wood based floor. The aim of this project is development of sound insulation systems consisting of wood based panel floor and ceiling in a wooden house. Experiments were made for various noise sources, materials and constructions. Some of newly obtained results are concluded as follows:1) There exists positive, linear correlation between La (overall value of sound pressure level in A-characteristics) and Lc (in C-characteristics).2) Reduction levels of floor impact noise are linearly correlated to the plane density of floor materials.3) In tapping noise, the sound pressure levels decreased by 525 dB by setting ceilings, by 10-35 dB by floating floors or sound barriers, and by 12-40 dB by the ceilings, floating floors. and sound barriers.4) In tire drop noise and foot step noise, the sound pressure levels decreased by the above systems by 2-16 dB and 5-25 dB, respectively.5) Radiation factors of floor impact noise were determined from the relationship between noise levels and vibration accelator. The factors are in satisfactory agreement with those from Beranek's equation. The sound pressure levels could be predicted with the factors.