Patent ID: 8261876

Claim:
A sound insulating trim part, comprising: at least one absorbing area with a sound absorbing characteristic, wherein the absorbing area comprises at least a first portion of a porous fibrous layer formed of a material having a dynamic Young's modulus; and at least one insulating area with an acoustic mass-spring characteristic, wherein the insulating area further includes: a mass layer; and a decoupling layer adjacent the mass layer, the decoupling layer comprised of a solid-phase material, wherein the mass layer further includes: a second portion of the same porous fibrous layer material included in the absorbing area, the second portion being adjusted to have a dynamic Young's modulus (Pa) of at least about (96·AW·t), with AW being an area weight (g/m 2 ), and t being a thickness (mm) of the porous fibrous layer; and a barrier layer, between the porous fibrous layer and the decoupling layer, that is substantially air impervious, and wherein the thickness of the first portion of the porous fibrous layer in the absorbing area is larger than the thickness of the second portion of the same porous fibrous layer in the insulating area.