Etude et réalisation d'une cabine de simulation pour l'évaluation psychoacoustique de la gêne induite au sol par un bang supersonique
Résumé
The aim of our work is to study loudness and annoyance of sonic boom. For that a specific listening tool must be designed. This is necessary because most of the power of the sonic boom is at very low frequencies, around 3Hz. Such low frequencies are perceived by the whole human body, then to assess the annoyance of sonic booms through listening tests requires to immerse the listener in a field as close as possible to the field in actual situations. Conversely, the strong transients existing in sonic booms lead to a significant spectrum content at higher frequencies. Together, these two aspects put a very high stress on the reproduction system, which has to reproduce the test signals with a high fidelity from very low to high frequencies. The design of this tool is made of a closed cabin which walls recovered with absorbing materials, so it can be considered as almost semi-anechoic at high frequencies. At lower frequencies, a multichannel loudspeaker system generates a high volumic velocity by driving loudspeakers mounted in the walls of the closed volume, leading to a high pressure down to very low frequencies. Performances of the simulation has been checked through measurements and psychoacoustic tests.