Abstract: Sound attenuation panel for aircraft having a combination of acoustic attenuation properties. The acoustic panel includes an acoustic structure having a cellular structure and a resistive skin and a backing skin, the acoustic panel also including at least one auxiliary acoustic device with cavities that is configured to produce additional acoustic absorption, the auxiliary acoustic device with cavities being attached to the acoustic structure and including adjacent chambers or cavities separated by shared walls, each of the chambers or cavities having perforations and being adapted to produce acoustic absorption. The combination of the acoustic structure and the auxiliary acoustic device with cavities enables combination of the acoustic absorption properties of these two types of element and an increased range of frequencies of the noise that can be attenuated by the acoustic panel without increasing its overall size.

Abstract: Sound attenuation panel for aircraft having a combination of acoustic attenuation properties. The acoustic panel includes an acoustic structure having a cellular structure and a resistive skin and a backing skin, the acoustic panel also including at least one auxiliary acoustic device with cavities that is configured to produce additional acoustic absorption, the auxiliary acoustic device with cavities being attached to the acoustic structure and including adjacent chambers or cavities separated by shared walls, each of the chambers or cavities having perforations and being adapted to produce acoustic absorption. The combination of the acoustic structure and the auxiliary acoustic device with cavities enables combination of the acoustic absorption properties of these two types of element and an increased range of frequencies of the noise that can be attenuated by the acoustic panel without increasing its overall size.

Abstract: A structure establishing a sound insulator and including a first plate, a second plate having holes therethrough, and a web stuck between the plates. The web includes a plurality of intermediate strips perpendicular at least to one of the plates, a plurality of folded strips which are folded in a zig-zag formation, each folded strip being arranged between two successive intermediate strips, and establishes, with the intermediate strips, triangular prisms, where, for two folded strips on either side of a same intermediate strip, the generator of the triangular prism of one of the folded strips forms an acute angle with respect to the first plate, and the generator of the triangular prism of the other folded strip forms an obtuse angle with respect to the first plate.