A study on normal incident sound absorption characteristics of Japanese traditional cedar board, yakisugi

Yakisugi is made by charring the surface of a cedar board to form a thin carbonized layer, which is said to improve durability, weatherability and fire resistance. It is a traditional Japanese exterior material that has become popular overseas due to its performance and visual texture. Recently, it has been attracting attention for its use as an interior material, but its basic performance is still unknown. In this study, we focus on the sound absorption characteristics of yakisugi as one of the investigations to understand its performance as an interior material. The carbonized layer of yakisugi is expected to have sound absorbing performance because of its porous nature. As a basic investigation, the sound absorption characteristics at normal incidence are measured using an impedance tube and compared with the carbonized layer conditions. It is found that yakisugi has sound absorption performance in the high frequency range. Moreover, the characteristics are depending on the thickness and surface properties of the carbonized layer.