Revision of Japanese guidelines for the prevention of noise-induced impairments in 2023

In Japan, the guideline for the prevention of noise-induced impairments published in 1984 was revised in 2023. The revisions include changes to the definition of target workplaces, methods for measuring noise levels, and methods for selecting hearing protection equipment. Additionally, prior to the revision of the guidelines, Japanese industrial standard (JIS) regarding the method for measuring the sound attenuation performance of hearing protectors was established in 2020. The old JIS was a product standard, but it was changed to a method standard with the ISO standard as an international standard. The new JIS has adopted single number rating (SNR) as an evaluation index. In recent years, Japan's guidelines and standards related to occupational noise have been internationally harmonized, but currently they are only published in Japanese. In this paper, an overview of the guidelines for the prevention of noise-induced impairments revised in 2023 will be mainly presented. This paper also introduces measuring device for noise exposure level, fit testing equipment, and real-ear attenuation at threshold (REAT) testing currently available in Japan. An overview of the new JIS was previously reported at inter-noise conference in 2021.