Broadband acoustic absorbers may be capable providing good absorption performance between 0 and 3,000 Hz, and particularly below 1,000 Hz. Reeds may be incorporated in a single layer, multiple layers, or bundles. Such broadband acoustic absorbers may be applied for acoustic absorption in aircraft, spacecraft, residential and commercial buildings, vehicles, industrial environments, wind tunnels, or any other suitable environment or application where noise reduction is desired.

A fairing for a power generation machine, the fairing comprising: a first layer comprising a metallic material; a second layer comprising a composite; and a third layer positioned between the first layer and the second layer, the third layer being configured to attenuate acoustic waves over a predetermined frequency range.

A fairing for a power generation machine, the fairing comprising: a first layer comprising a metallic material; a second layer comprising a composite; and a third layer positioned between the first layer and the second layer, the third layer being configured to attenuate acoustic waves over a predetermined frequency range.

Noise attenuating trim part for a vehicle comprising a pile layer, a bonding mass layer and a backing layer whereby the bonding mass layer is bonded to the adjacent layers whereby the bonding mass layer is comprising at least thermoplastic elastomeric polyolefin based compound material (TPO) with a filler content of at least 55%, and whereby

the bonding mass layer has a density of between 1.4 and 1.75 kg/dm.sup.3, a viscosity of less than 50.000 mPa.s and a MFI above 250 and whereby the bonding mass layer is adjacent the pile layer and partly penetrated into the lower area of the pile thereby binding the fibers and/or filaments and/or the tufts within the pile.

A sound damping wallboard and methods of forming a sound damping wallboard are disclosed. The sound damping wallboard comprises a gypsum layer with a gypsum surface having an encasing layer. The encasing layer is partially removed to expose the gypsum surface and form a gypsum surface portion and a first encasing layer portion on the gypsum layer. A sound damping layer is applied to the gypsum layer to cover at least part of the gypsum surface portion and the encasing layer portion.

A sound damping wallboard and methods of forming a sound damping wallboard are disclosed. The sound damping wallboard comprises a gypsum layer with a gypsum surface having an encasing layer. The encasing layer is partially removed to expose the gypsum surface and form a gypsum surface portion and a first encasing layer portion on the gypsum layer. A sound damping layer is applied to the gypsum layer to cover at least part of the gypsum surface portion and the encasing layer portion.

A soundproof member includes: a first elastic porous body layer; a first film layer; a second elastic porous body layer; and a second film layer, the layers arranged in the stated order from a sound source (S) side, wherein the first and second elastic porous body layer each have: a thickness of 0.5 mm or more and 10 mm or less; a bulk density of 45 kg/m.sup.3 or more and 550 kg/m.sup.3 or less; and a Young's modulus of 7,000 Pa or more and 28,000 Pa or less, and wherein a total (L1/Λ1+L2/Λ2) of a ratio (L1/Λ1) of the thickness L1 (mm) of the first elastic porous body layer to a viscous characteristic length Λ1 (μm) thereof and a ratio (L2/Λ2) of the thickness L2 (mm) of the second elastic porous body layer (20) to a viscous characteristic length Λ2 (μm) thereof is 0.11 or more.

A soundproof member includes: a first elastic porous body layer; a first film layer; a second elastic porous body layer; and a second film layer, the layers arranged in the stated order from a sound source (S) side, wherein the first and second elastic porous body layer each have: a thickness of 0.5 mm or more and 10 mm or less; a bulk density of 45 kg/m.sup.3 or more and 550 kg/m.sup.3 or less; and a Young's modulus of 7,000 Pa or more and 28,000 Pa or less, and wherein a total (L1/Λ1+L2/Λ2) of a ratio (L1/Λ1) of the thickness L1 (mm) of the first elastic porous body layer to a viscous characteristic length Λ1 (μm) thereof and a ratio (L2/Λ2) of the thickness L2 (mm) of the second elastic porous body layer (20) to a viscous characteristic length Λ2 (μm) thereof is 0.11 or more.

There is provided an acoustically treated landing gear door for reducing noise from a landing gear of an aircraft. The acoustically treated landing gear door includes a landing gear door for attachment to the aircraft. The landing gear door includes an acoustic treatment assembly integrated on an inner mold line of an interior side, and extending within an interior cavity of the landing gear door. The acoustic treatment assembly includes a core structure having a first side and a second side, a plurality of core cells extending between the first side and the second side, and a drainage system. The acoustic treatment assembly further includes an acoustic facesheet and a nonporous backsheet. The acoustically treated landing gear door reduces the noise from the landing gear, when the landing gear is in a deployed position, by attenuating acoustic waves emanating from the landing gear and reflected off the acoustic treatment assembly.

There is provided an acoustically treated landing gear door for reducing noise from a landing gear of an aircraft. The acoustically treated landing gear door includes a landing gear door for attachment to the aircraft. The landing gear door includes an acoustic treatment assembly integrated on an inner mold line of an interior side, and extending within an interior cavity of the landing gear door. The acoustic treatment assembly includes a core structure having a first side and a second side, a plurality of core cells extending between the first side and the second side, and a drainage system. The acoustic treatment assembly further includes an acoustic facesheet and a nonporous backsheet. The acoustically treated landing gear door reduces the noise from the landing gear, when the landing gear is in a deployed position, by attenuating acoustic waves emanating from the landing gear and reflected off the acoustic treatment assembly.