An impact damping mat comprises a plurality of layers arranged in a stacked formation. The stacked formation has a total thickness of no greater than 4 7/16 inches. The plurality of layers cooperate to provide the impact damping mat with at least one of a coefficient of restitution no greater than 30% and a selected sound reduction characteristic. The selected sound reduction characteristic can be a reduction of a maximum sound level of at least 5 dB from 40 to 63 Hz octave bands and at least 13 dB at and above 80 Hz octave bands normalized to a conventional inch rollout rubber flooring product.

Acoustic structures in which acoustic septa are located in the cells of a honeycomb for reducing the noise generated from a source. The honeycomb used to form the acoustic structure has walls that contain convex and concave contours which make the honeycomb flexible. The acoustic septa are formed by inserting planar acoustic inserts into the honeycomb cells to form a septum cap which is friction-locked within the cell and then permanently bonded in place. The planar acoustic septum is configured to match the unique shape of the cell contours to provide desired friction-locking when inserted into the cells and desired acoustic properties after being permanently bonded in place.

A composite structure for improving the acoustical properties of a low NRC membrane including a sound absorbing layer and a porous, scrim covered, perforated drywall layer.

An impact damping mat comprises a plurality of layers arranged in a stacked formation. The stacked formation has a total thickness of no greater than 4 7/16 inches. The plurality of layers cooperate to provide the impact damping mat with at least one of a coefficient of restitution no greater than 30% and a selected sound reduction characteristic. The selected sound reduction characteristic can be a reduction of a maximum sound level of at least 5 dB from 40 to 63 Hz octave bands and at least 13 dB at and above 80 Hz octave bands normalized to a conventional inch rollout rubber flooring product.

A soundproof structure includes two or more kinds of resonant type sound absorbing cells including different kinds of a first resonant type sound absorbing cell and a second resonant type sound absorbing cell that are adjacent to each other; and an opening part provided in the second resonant type sound absorbing cell, in which a resonance frequency of the first resonant type sound absorbing cell and a resonance frequency of the second resonant type sound absorbing cell match each other. As a result, the soundproof structure is capable of achieving an absorptance of more than 50%, preferably, close to 100% even in a compact, light, and thin structure which is much smaller than a wavelength, thereby obtaining a high soundproofing effect. Further, the soundproof structure is capable of obtaining air permeability and/or heat conductivity by providing a passage of air and/or heat.

The present disclosure provides acoustic structures and related systems and methods which may be used to dampen or attenuate sound waves, including, for example, noise generated by or emanating from various aspects or components of turbomachines such as turbine engines. These acoustic structures include oblique polyhedral cellular structures, including converging polyhedral cells and diverging polyhedral cells, and related systems and methods of making and using such acoustic structures.

A laminated structure for use in retrofit building construction (partition, wall, ceiling, floor or door) that exhibits improved acoustical sound proofing characteristics while being optimized for efficient installation. The laminated structure includes a panel with at least one layer of viscoelastic glue, or fire-10 resistant, viscoelastic glue, which functions both as a glue and an energy dissipating layer. In one embodiment, the laminated structure to be attached to an existing wall in some embodiments includes standard paper-faced gypsum board. In another embodiment the to-be-applied laminated structure includes a cement-based board, and in yet another embodiment the to-be-applied laminated 15 structure includes a cellulose-based board. Once the laminated structure is installed on an existing wall or other partition, the resulting structure greatly attenuates transmitted noise and minimizes the labor required for installation and finishing.

An acoustic system is disclosed. The acoustic system includes a number of acoustic panel sections having a variety of acoustic properties. Each acoustic panel section is configured to be mounted on an interior surface of a building and cooperates with the other acoustic panel sections to define a pattern on the interior surface of the building.

A sound absorbing cell according to an exemplary embodiment of the present invention is formed of a plurality of plates that are stacked while interposing an air layer therebetween, wherein the plurality of plates include: a reflective plate that is disposed outermost from a space where sound is generated; and a microperforated plate that is stacked on the reflective plate and having a plurality of holes perforated therein.

Acoustic structures in which acoustic septa are located in the cells of a honeycomb for reducing the noise generated from a source The honeycomb used to form the acoustic structure has walls that contain convex and concave contours which make the honeycomb flexible. The acoustic septa are formed by inserting planar acoustic inserts into the honeycomb cells to form a septum cap which is friction-locked within the cell and then permanently bonded in place. The planar acoustic septum is configured to match the unique shape of the cell contours to provide desired friction-locking when inserted into the cells and desired acoustic properties after being permanently bonded in place.