Laboratory of Wood Science, Division of Sustainable Bioresources Science, Department of Agro–environmental Sciences, Faculty of Agriculture, Kyushu University
九州大学大学院農学研究院環境農学部門サスティナブル資源科学講座木質資源科学研究分野
To estimate changes in the acoustic properties of a wooden xylophone keyboard caused by heat treatment, the resonant frequencies and logarithmic decrement of control and heat–treated specimens of Yezo spruce (Picea jezoensis), Northern red oak (Quercus rubra) and Japanese red pine (Pinus densiflora S. et Z.) were evaluated by the free vibration method. A flexural vibration test was carried out by the xylophone stick free fall impact test. The changes in resonant frequency of the first mode and those of other modes by heat treatment were evaluated. And the changes in logarithmic decrement by heat treatment were evaluated. As a result of heat treatment, the resonant frequencies of the 1st mode of all specimens were decreased, and within a species the wood specimens of higher resonant frequencies were more influenced. In the case of the specimen with a higher resonant amplitude at the 2nd mode resonance frequency, the resonant amplitude of the 1st mode resonance frequency was increased more by heat treatment, so that the sound became more stable.