Abstract: Methods, systems, and apparatuses are disclosed for reducing sound level, by providing enclosures comprising enclosure walls having integral tunable resonator cavities, and reducing sound levels within the enclosure in response to detected sound levels outside of the enclosure.

Abstract: An impact-compensating bucking bar and its use to reduce impacts during riveting, where the bucking bar includes a body; a strike surface on a distal portion of the body, a compensating inertial mass coupled to the body by a flexible and resilient mass support, and a handgrip coupled to the body and configured for the user to urge the strike surface of the bucking bar against a tail of a rivet to facilitate upsetting the rivet tail during riveting. A relative movement of the compensating inertial mass of the bucking bar in response to a strike on the rivet head at least partially dissipates energy imparted to the body during riveting, reducing impact stresses on the bucking bar user.

Abstract: An impact-compensating bucking bar and its use to reduce impacts during riveting, where the bucking bar includes a body; a strike surface on a distal portion of the body, a compensating inertial mass coupled to the body by a flexible and resilient mass support, and a handgrip coupled to the body and configured for the user to urge the strike surface of the bucking bar against a tail of a rivet to facilitate upsetting the rivet tail during riveting. A relative movement of the compensating inertial mass of the bucking bar in response to a strike on the rivet head at least partially dissipates energy imparted to the body during riveting, reducing impact stresses on the bucking bar user.

Abstract: A method for effecting a machine-based determination of speech intelligibility in an aircraft during flight operations includes: (a) in no particular order: (1) providing a representation of a machine-based speech evaluating signal; and (2) providing a representation of in-flight noise; (b) combining the representation of a machine-based speech evaluation signal and the representation of in-flight noise to obtain a combined noise signal; and (c) employing the combined noise signal to present the machine-based determination of speech intelligibility in an aircraft during flight operations.

Abstract: A method for effecting a machine-based determination of speech intelligibility in an aircraft during flight operations includes: (a) in no particular order: (1) providing a representation of a machine-based speech evaluating signal; and (2) providing a representation of in-flight noise; (b) combining the representation of a machine-based speech evaluation signal and the representation of in-flight noise to obtain a combined noise signal; and (c) employing the combined noise signal to present the machine-based determination of speech intelligibility in an aircraft during flight operations.