A capsule contains fluid and a solid inertial mass that is free to move within the capsule. The capsule is embedded in a foam panel. A plurality of such foam panels are attached to the internal wall of a launch vehicle fairing. This device augments acoustic energy dissipation with damping the resonant frequency of the fairing to reduce the amount of energy that is transmitted into the acoustic volume contained within the wall. Incorporating a plurality of capsules respectively tuned to many frequencies provides broadband structural attenuation. This abstract is provided to comply with the rules requiring an abstract, and is intended to allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.