Acoustic characteristics of nonwood baseball bats following revised Japanese Product Standards (Safe Goods (SG) Standards)

In this study, we measured the acoustic characteristics of nonwood baseball bats modified according to the Revised Japanese Product Standards (hereafter, Safe Goods (SG) Standards) enforced in 2024. New standard bats showed peak frequencies approximately 500 Hz higher than previous models. During Spring Koshien 2024, players reported differences in bat sound and ball travel distance, with the onomatopoeic description changing from “kakkin” to “kyu-in” following the revision, according to various media. The results of acoustic measurements conducted in compliance with the SG Standards confirm the observations of the players, indicating a tonal shift in the bats after the SG Standards were revised.