Soundscape design using sound tube—To listen to voices, waves, wind, and footsteps

In modern public architecture, a large amount of glass is often used as the material, and the space is visually connected by its transparency. However, on the other hand, the soundscape is divided. In the project of “Chino Cultural Complex,” we intended to connect the two spaces through sound. This consists of a sound tube running approximately 20 m through underground of the courtyard. By speaking into one end of the tube, participants can converse with counterparts only faintly visible on the other side, with the voice as clear as if they were close to the ear. In this paper, we show the basic experiment of the sound tube in the anechoic chamber. We found an appropriate diameter of the tube in which the human voice was easy propagating on each other. Then, sound tube is covered with the absorbing materials and is set by the anti-vibrating suspension in the box culvert on site. The anti-vibration structure protected transmission of the structure-bone sound except voices to the sound tube. In other projects, we have designed this sound tube to listen to sound of waves, wind, and footsteps. We hope that these activities will provide significant soundscape design.