System for determining an interior or exterior acoustic noise level of an enclosed structure and noise reduction device incorporating such system

摘要

The acoustic noise monitor determines acoustic sound levels radiated or scattered to an exterior or interior fluid space of a structure such as an enclosed structure by measuring a condition, such as strain level, of the structure itself rather than by directly measuring the fluid itself. From the strain or other condition measured on the structure, the acoustic sound levels can be calculated with the Helmholtz integral. The sensors on the structure are preferably spaced so that non-radiating high wave-number motions of the structure are averaged out. The acoustic noise monitor can be used with submarines, jet aircraft, cars, or the like.