Sound environment design using flexible wood-based sound absorbers

A sound-absorbing material made of flexible wooden boards with air permeability was developed to improve the indoor sound environment of buildings. The flexible wood-based material has sound absorbing characteristics with the Helmholtz resonator by its air permeability. In other words, various sound absorption characteristics could be realized owing to the cross-sectional shape (flat or curved) and machining conditions (cut width, cut pitch, and plate thickness). In this paper, the application of flexible wood-based sound-absorbing materials to acoustic design in actual buildings (nursery schools and a church) where acoustic considerations are required is presented. In their application to a newly built nursery school, one of the considerations was to prevent the loss of design by installing sound-absorbing materials. In their application to acoustic renovation, the sound environment improvement effect was confirmed by measuring sounds before and after the installation, and it was also confirmed that the users were able to feel the improvement effect. These results will lead to the development of sound-absorbing wooden boards as an interior material and the promotion of the use of wood in buildings to contribute to the realization of a decarbonized society.