An acoustic fiber silencer for a motor vehicle includes a first sound absorbing layer and a second sound insulating layer. The layers are formed of lightweight fibrous material, and the sound insulating layer is quilted. The acoustic fiber silencer includes a frame to which the sound absorbing and sound insulating layers are secured. The frame provides structural support and shape to the sound absorbing and sound insulating layers. The acoustic fiber silencer is lightweight while maintaining excellent noise attenuation properties.