The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 20, 2000
Filed:
Oct. 03, 1997
Andreas H von Flotow, Hood River, OR (US);
Mathieu Mercadal, Hood River, OR (US);
Peter M Tappert, Hood River, OR (US);
Hood Technology Corporation, Hood River, OR (US);
Abstract
In aircraft, much of the noise in the cabin is a result of pressure fluctuations on the exterior fuselage skin, which vibrates the skin and causes sound pressure waves to propagate through the trim panel cavity, exciting the trim panels, which radiate into the cabin. In the present invention, noise is reduced in the cabin of an aircraft by reducing the acoustical impedance of the trim panel cavity of the aircraft using an array of independent active sound absorbing acoustic cells. Acoustical drivers are mounted within the trim panel cavity of the aircraft. Each acoustical driver has at least one electroacoustical sensor mounted in its immediate vicinity. The sensor is connected to the driver to provide negative feedback, which has the effect of canceling noise in the vicinity of each cell. Since the effect of each cell is to absorb acoustical energy, the acoustical impedance of the trim panel cavity is reduced. Multiple sound absorbing acoustic cells in the trim panel cavity therefore decrease the acoustical impedance inside the trim panel cavity which in turn reduces the transmission of noise into the cabin.