PT Journal AU Ervin, L Miroslav, B Monika, B TI Porous Sound Absorbers and Determination of their Acoustical Properties SO Acta Mechanica Slovaca PY 2011 BP 28 EP 32 VL 15 IS 2 DI 10.21496/ams.2011.015 DE Porosity; Flow Resistivity; Tortuosity; Measurement AB One of the most frequent problems faced by noise control engineers is how to design sound absorbers that provide the desirable sound absorption coefficient that minimizes the size and cost, does not introduce any environmental hazards, and stands up to hostile environments. The designers of sound absorbers must know how to choose the proper sound absorbing materials, its geometry and the protective facing. Porous sound-absorbing materials are utilized in almost all areas of noise control engineering. This paper deals with the acoustical parameters of porous materials and their measurement. ER