Abstract
This paper showes the results of experiment about floor impact sound (by heavy impact source) of wooden structure. First, we tested it with a scale model (S1 : 4), and understood that both the upper floor structure and the wall of lower room should be improved to reduce floor impact sound and the following (1)〜(3) were considered as a structure which can reduce it fairly. (1) The lower room has double wall. One supports upper floor structure (outer wall), the other supports ceiling of the lower room (inner wall). The outer structure without panels is better than the one with panels, because such structure has smaller sound radiating area than with panel. (2) The floor panel has many small holes to reduce sound radiation resistance. (3) The ceiling has rather high transmission loss. After the scale model tests were over, we confirmed them with using an actual size structure, and it was certained that we were able to make a wooden structure which grade was L-55.
