SYSTEM FOR DAMPENING NOISE GENERATED BY A GAS TURBINE ENGINE

A system for dampening noise generated by a gas turbine engine is disclosed. In various embodiments, the system includes a fan exit guide vane (140; 240; 440) having a leading edge (256), a trailing edge (258) and a pocket (279) that extends in a chordwise direction between the leading edge (256) and the trailing edge (258); and an acoustic panel (250; 350; 450) configured to be received within the pocket (279), the acoustic panel (250; 350; 450) including a back sheet (262; 362; 462), a face sheet (260; 360; 460) and a core disposed between the back sheet (262; 362; 462) and the face sheet (260; 360; 460), the core having a first cavity (272; 372; 472) extending between a first wall (271; 371; 471) and a second wall (273; 373; 473) and a second cavity (274; 374; 474) disposed within the first cavity (272; 372; 472).