Patent ID: 7137477

Claim:
A sound absorber consisting of two interconnected non-woven fabrics bonded through at least one of a thermoplastic and a thermoset materials, wherein the first non-woven fabric facing towards the sound-emitting source has a layer thickness within a range of from 2 to 15 mm, a density within a range of from 50 to 500 kg/m 3 , a weight per surface area within a range of from 0.1 to 2.5 kg/m 2 , and a flow resistance within a range of from 50 to 1000 kNs/m 4 , and the second non-woven fabric facing away from the soundemitting source has a layer thickness within a range of from 10 to 28 mm, a density within a range of from 20 to 100 kg/m 3 , a weight per surface area within a range of from 0.4 to 1 kg/m 2 , and a flow resistance within a range of from 10 to 40 kNs/m 4 , with a total thickness of the sound absorber within a range of from 12 to 30 mm and a total weight per surface area of the sound absorber within a range of from 0.5 to 3 kg/m 2 .