A sound insulation system for use with a vehicle includes a layer of
fibrous padding material having a first surface and an opposite second
surface. The first surface includes multiple spaced apart recesses. The
second surface includes a substantially flat surface portion that extends
over two adjacent recesses. The multiple recesses are configured to
define multiple voids when the sound insulation system is mounted in the
vehicle, thereby enhancing acoustical performance of the sound insulation
system.