Abstract: A noise-suppression assembly of a mechanical drive system having a rotational frequency includes an audio filter unit configured to receive a first audio signal and a timing signal of the mechanical drive system. The audio filter unit generates a noise-cancellation signal based on a frequency of the timing signal to suppress a noise generated by the mechanical drive system and to apply the noise-cancellation signal to the first audio signal to produce a filtered first audio signal. The frequency of the timing signal is based on the rotational frequency of the mechanical drive system.

Abstract: A noise-suppression assembly of a mechanical drive system having a rotational frequency includes an audio filter unit configured to receive a first audio signal and a timing signal of the mechanical drive system. The audio filter unit generates a noise-cancellation signal based on a frequency of the timing signal to suppress a noise generated by the mechanical drive system and to apply the noise-cancellation signal to the first audio signal to produce a filtered first audio signal. The frequency of the timing signal is based on the rotational frequency of the mechanical drive system.

Abstract: An airframe includes a mass barrier layer mounted to a multitude of frame members and adjacent to each of a multitude of foam portions to provide a contiguous layer to seal the foam portions within the respective multitude of frame voids.

Abstract: An acoustic absorption blanket mounting system includes a blanket mounting strip (BMS) attached to a fastener strip mounted to an airframe member. The BMS is generally of a shape to removably capture a sound proofing blanket between opposed pair of wings. At least one wing of the pair of wings includes an acoustic gasket strip sewn to the BMS base material layer. Opposed blanket hook and loop strips correspond to wing hook and loop strips such that a soundproofing blanket is retained between the wings such that the acoustic gasket strip minimizes acoustic leakage heretofore experienced in soundproofing blanket attachments.

Abstract: A tunable acoustic absorption system according to the present invention includes an airframe batting area; a primary soundproofing blanket area; an interior trim panel area; and a hard trim area, which are layered over an aircraft outer skin. Specifically tailoring or “tuning” materials within each area to the particular aircraft acoustic signature achieves significant increases in acoustic absorption achieved over conventional generic sound treatments.

Abstract: A tunable acoustic absorption system according to the present invention includes an airframe batting area; a primary soundproofing blanket area; an interior trim panel area; and a hard trim area, which are layered over an aircraft outer skin. Specifically tailoring or “tuning” materials within each area to the particular aircraft acoustic signature achieves significant increases in acoustic absorption achieved over conventional generic sound treatments.

Abstract: A structural damping assembly includes a bonding plate, a stiffener layer, an elastomeric layer, and a constraining layer. The elastomeric layer is boned between the stiffener layer and the constraining layer. The bonding plate and the stiffener layer extend between, and are preferably in contact with, webs which form a pocket on a substrate such as a transmission support beam. The structural damping assembly uses the energy dissipating properties of the elastomeric layer that is sandwiched between the vibrating stiffener layer and the constraining layer to combat noise due to resonant response while operating as a stiffener that increases the frequency of resonance to a range where coincidental placement with an excitation frequency is reduced.

Abstract: An acoustic absorption trim panel includes a composite core, a decoupler layer, and a mass barrier layer. By ensuring that the mass barrier layer remains limp in a limp area but in contact with the composite core through the decoupling layer, damping greater than that imparted in conventional construction is achieved.