To predict the heavy floor impact sound insulation, the concrete slab performance is calculated at the beginning. Moreover, the reduction performance of the floor finish structure is added to the result. Thus, it is essential to reduce prediction error about the concrete slab performance.
The impedance method is used to predict the performance of the heavy floor impact sound of concrete slabs. The difference between the calculation result of the heavy floor impact sound by impedance method and the experimental result is affected by the error due to the condition setting of calculation and the parameters’ averaging error.
The driving-point impedance in impact time and the basic impedance level were compared to confirm the error’s influence due to the condition setting. The results confirmed that a good correspondence was obtained by using the actual slab thickness and Young’s modulus of the concrete. Thus, the error due to the condition setting of calculation can be reduced by considering the site’s construction condition and managing it accurately at the site.
It is necessary to improve the amount of impedance reduction by resonance because the driving-point impedance in the response time has a large prediction error even at the point, without edge fixing influence. Thus, we propose a method using an approximate function to calculate the amount of impedance reduction by resonance.
It was confirmed that the amount of impedance reduction by resonance significantly affects the parameters’ averaging error. It was also confirmed that the prediction error can be reduced using the approximate function that is continuous at this parameter.
Although some prediction error remains even if these results are used, considering the impedance method versatility, it is better to express the calculation result that includes the error.