US Patent 7070848 Vehicle acoustic barrier

An acoustic barrier that achieves excellent noise insulating properties, and is relatively thin and relatively light in weight includes a flexible thermoplastic barrier layer having a plurality of apertures defining a latticed structure which includes apertures for pass-through components and non-pass-through apertures. The non-pass-through apertures are located where noise levels are expected or known to be relatively low. Effective acoustic performance can be maintained by completely eliminating material from the relatively thick and dense barrier layer at the low noise levels areas, and providing only absorptive decoupler material and/or lightweight sheet material such as plastic films in those areas.