Airborne acoustic absorbers include periodic arrays of Helmholtz resonators that are covered and/or partially filled with an acoustically absorptive material, such as a thermoplastic foam. The combined structures have much broader frequency ranges of high acoustic absorption than do structures having only Helmholtz resonators or acoustically absorbing foam.

A wall panel has a block of base material, e.g., expanded polystyrene. A resonator tube is disposed in the block. A sound dampening material is disposed in the resonator tube. The sound dampening material can be recycled mattress or carpet. An inlet pipe extends into the resonator tube. A vent is disposed over the inlet pipe. A barrier wall can be formed by stacking multiple wall panels. Additional resonator tubes can be disposed between the wall panels.

Airborne acoustic absorbers include periodic arrays of Helmholtz resonators that are covered and/or partially filled with an acoustically absorptive material, such as a thermoplastic foam. The combined structures have much broader frequency ranges of high acoustic absorption than do structures having only Helmholtz resonators or acoustically absorbing foam.

A wall panel has a block of base material, e.g., expanded polystyrene. A resonator tube is disposed in the block. A sound dampening material is disposed in the resonator tube. The sound dampening material can be recycled mattress or carpet. An inlet pipe extends into the resonator tube. A vent is disposed over the inlet pipe. A barrier wall can be formed by stacking multiple wall panels. Additional resonator tubes can be disposed between the wall panels.

A sound insulation device (1) for reducing sound transmission, comprising an arrangement of mechanical resonators (2), which each contain at least one vibrating mass (3) and a spring element (4), wherein the mechanical resonators (2) are each tuned such that each resonator has at least one natural frequency in a relevant frequency range, wherein the arrangement of mechanical resonators (2) is configured such that it generates at least one stop band for the propagation of waves in the relevant frequency range.