Importance

Loading Importance Indicators...

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.

Loading the Abstract Image...

First Claim