Example methods, panels, and systems are disclosed for providing noise insulation. Noise insulation may be provided by an anti-resonant panel that includes a base panel including a base panel core material and two base panel face sheets, where each of the two base panel face sheets is adjacent to an opposite side of the base panel core material. The anti-resonant panel further includes at least one stiffener-member positioned along the base panel in a defined area of the base panel, where the defined area is less than a full area of the base panel. The stiffener-member includes a stiffener-member core material and two stiffener-member face sheets the stiffener-member face sheets adjacent to an opposite side of the stiffener-member core material.