Abstract: A multilayered acoustic panel (1) including: a substantially air impermeable outer membrane layer (3); an underlying second portion bonded to the membrane layer (3), the second portion including an intermediate layer (5); and an inner layer (7) underlying the second portion, the inner layer (7) having a plurality of apertures (6) therein, said apertures (6) being covered by the intermediate layer (5) of the second portion, wherein the membrane layer (3) and second portion are not bonded together where the membrane layer (3) overlies the apertures (6) such that those portions of the membrane layer (3) which overlie the apertures (6) are free to vibrate independently of the second portion in response to sound waves incident on the membrane layer (3).

Abstract: A panel (1) including a substantially air impermeable membrane layer (3) and a layer (5) having apertures (6) therein, wherein each portion of the membrane layer (3) which overlies an aperture (6) defines a diaphragm (9) which is able to vibrate in response to sound waves incident on the membrane layer (3) and thereby absorb at least part of the sound waves' energy, at least some of the apertures (6) being arranged in clusters (11) whereby the greatest distance between adjacent apertures within a cluster (11) is less than the distance between (i) any one of the apertures (6) within the cluster (11) and (ii) any aperture (6) outside of the cluster (11), each region of the panel (1) defined by an outer periphery of a cluster (11) forming a resonance absorber (13) which is able to vibrate in response to sound waves and thereby absorb at least part of the sound waves energy, wherein at least one resonance absorber (13) is able to provide sound absorption at a frequency which is different to the frequency of reson

Abstract: A multilayered acoustic panel (1) including: a substantially air impermeable outer membrane layer (3); an underlying second portion bonded to the membrane layer (3), the second portion including an intermediate layer (5); and an inner layer (7) underlying the second portion, the inner layer (7) having a plurality of apertures (6) therein, said apertures (6) being covered by the intermediate layer (5) of the second portion, wherein the membrane layer (3) and second portion are not bonded together where the membrane layer (3) overlies the apertures (6) such that those portions of the membrane layer (3) which overlie the apertures (6) are free to vibrate independently of the second portion in response to sound waves incident on the membrane layer (3).

Abstract: A panel (1) including a substantially air impermeable membrane layer (3) and a layer (5) having apertures (6) therein, wherein each portion of the membrane layer (3) which overlies an aperture (6) defines a diaphragm (9) which is able to vibrate in response to sound waves incident on the membrane layer (3) and thereby absorb at least part of the sound waves' energy, at least some of the apertures (6) being arranged in clusters (11) whereby the greatest distance between adjacent apertures within a cluster (11) is less than the distance between (i) any one of the apertures (6) within the cluster (11) and (ii) any aperture (6) outside of the cluster (11), each region of the panel (1) defined by an outer periphery of a cluster (11) forming a resonance absorber (13) which is able to vibrate in response to sound waves and thereby absorb at least part of the sound waves energy, wherein at least one resonance absorber (13) is able to provide sound absorption at a frequency which is different to the frequency of reson

Abstract: A multilayered acoustic shield (1) for mounting to a panel of a vehicle, the shield (1) including an outer portion and an inner portion, the outer portion including a support layer (5) having apertures (6) therein, the inner portion including a sound-absorbing layer (9) and a vibration-dampening layer (11), wherein the shield (1) is fastenable to the panel of the vehicle such that at least a portion of the dampening layer (11) engages the panel with the sound-absorbing layer (9) being compressed between the outer portion and the dampening layer (11), to thereby reduce the transmission of noise into a cabin of the vehicle.