JIS A 1418-2, which provides the measurement method of floor impact sound by standard heavy impact source, was vastly revised in January, 2000. It provides about the ball which has the different characteristic of impact force(II) from the tire before now. However, there has been a problem that big change of impact force by the ambient temperature, because the development has been executed for the ball made of rubber before now. Then, we tried to make the ball made of silicone-rubber, and examined the reasonability of heavy impact source from the point of view of impact force characteristic and floor impact sound.
