Absorption of sound Measurement 35 Acoustical engineering 27 Noise control 20 Sound 20 Transmission 20 Fibrous composites 14 Acoustical materials 13 Testing 12 Composite materials 11 Acoustic properties 10 Soundproofing 9 Mechanical properties 8 Fibers 7 Porous materials 4 Sound absorber 4 Mathematical models 3 Polyurethanes 3 Vibration 3 Anechoic chambers 2 Kenaf 2 Machinery 2 Natural fibre 2 Noise barriers 2 Sandwich construction 2 Spandex 2 Acoustics 1 Architectural acoustics 1 Automotive engineers 1 Biopolymer 1