Systems and methods are presented for dampening noise in a rotating machine having a rotatable shaft defining an axis of rotation. An acoustic panel assembly may comprise an annular casing, a hook, and an acoustic panel carried by the hook. The acoustic panel comprises a radially inner skin, a radially outer skin, and an acoustic treatment member having a plurality of walls extending between the radially inner skin and the radially outer skin thereby defining a plurality of radially oriented cells. A portion of the cells adjacent a first axial edge of the acoustic panel are filled with a reinforcement material and shaped to form a lip having sufficient strength to support a portion of the acoustic panel. The panel is positioned so that the lip is axially and radially retained by the hook.