Patent ID: 7971684

Claim:
Panel for acoustic treatment connected to a surface of an aircraft, from the outside to the inside, comprising: an acoustically resistive porous layer, at least one alveolar structure, and a reflective or impermeable layer, wherein said acoustically resistive porous layer comprises—at the outside surface that can be in contact with the aerodynamic flows—one sheet or piece of sheet metal comprising open zones ( 14 ) that allow sound waves to pass and filled zones ( 16 ) that do not allow sound waves to pass, and wherein the sheet or piece of sheet metal of the acoustically resistive layer comprises sets of microperforations ( 18 ), each set of microperforations forming one said open zone ( 14 ), wherein the filled zones ( 16 ) define bands for ensuring the structural function and the absorption of stresses, a first series of bands arranged in a first direction and a second series of bands arranged in a second direction that is secant with the first direction, the bands of each series being spaced so as to separate each set of microperforations ( 18 ), wherein the microperforations ( 18 ) have oblong shapes whose largest dimension is oriented in the direction of the flows that flow at the surface of the acoustically resistive layer, and wherein the microperforations ( 18 ) are aligned along several lines for the same set ( 14 ) and arranged in staggered rows from one line to the next.