PURPOSE: To estimate the sound-insulation performance of a floor constructed of a floor panel by a method wherein the sound-insulation performance of the floor constructed between a sound-source chamber on the upper story in a building and a sound-receiving chamber on the lower story can be evaluated purely and precisely and the sound-insulation performance of only the floor panel as a single body is measured.

CONSTITUTION: In order to measure the sound-insulation performance of a floor 4 constructed between a sound-source chamber 2 and a sound-receiving chamber 3 in a building 1, microphones 13 are set so as to be separated from the floor 4, vibration sensors 15 are attached to the floor 4, and shock sounds are generated in the floor 4 by floor-shock-sound generators 11, 12. Floor shock sounds which have been detected by the microphones 13 are octave-analyzed, floor vibrations which have been detected by the vibration sensors 15 are octave-analyzed, the sound-insulation performance of the floor is evaluated on the basis of the octave analysis of the floor shock sounds, the component of noises from a beam 6, a circumferential wall 7 and the like, which have been mixed with the floor shock sounds, is analyzed on the basis of both octave analyses, and the evaluation of the sound-insulation performance of the floor is corrected.