Review of floor impact sound insulation performance measurement evaluation methods and timber floor specifications in Japan

Since the 1970s, heavy-weight floor impact noise has been a concern in Japan, prompting the development of unique measurement and evaluation methods standardized by JIS (Japanese Industrial Standards). JIS A 1418-1 specifies the measurement method for light-weight floor impact sound insulation performance, while JIS A 1418-2 defines the measurement method for heavy-weight floor impact sound insulation performance. Two types of standard impact sources, namely car-tire impact source and rubber ball impact source, are specified for measuring the heavy-weight floor impact sound insulation performance. JIS A 1419-2 defines the evaluation method for floor impact sound insulation performance. These methods differ from the international ISO standards, making performance comparison challenging. This paper provides an overview of these Japanese methods. Furthermore, since the enforcement of "the Act on Promotion of Use of Wood in Buildings to Contribute to the Realization of a Decarbonized Society," construction of timber buildings has been promoted in Japan with the aim of encouraging wood usage and contributing to the SDGs (Sustainable Development Goals). However, the floor impact sound insulation performance of timber floors tends to be low, with various specifications for timber floor cross-sections differing among private companies. This paper introduces these specifications and also compares driving-point impedances.