A new experimental device for investigating vibro-acoustic effects of sonic booms in buildings

Reduction of sonic booms is one of the most important environmental challenges in overland supersonic flights. Since sonic booms differ from other transportation noise in the sense that they have abrupt pressure rises and significant acoustic energy at very low frequencies, special evaluation metrics and acceptability standards are necessary. Also, for practical evaluation of sonic booms in everyday life, sonic booms under both indoor and outdoor conditions need to be investigated. Since it is reported that annoyance induced by sonic booms is greater inside a building than outside due to, for example, vibration of buildings and rattling noise from windows, it is important to investigate the effects of sonic booms in indoor spaces. For this purpose, a new vibro-acoustic experimental device has been developed at Japan Aerospace Exploration Agency (JAXA). In this device, synthetic sonic booms are played through loudspeakers, and the sonic boom signatures before and after transmission through test architectural components (e.g., a wall material and a window), as well as vibrations of the test specimen, are measured. In this study, overview of the newly developed experimental device and preliminary results of vibro-acoustic experiments are reported.