Considerations on the Pore Geometry of Sound Absorbing Materials

The article contains a solution of the differential equation of sound propagation in porous media with boundary conditions and the calculation of specific acoustic impedance.

The sound absorption coefficient for normal incidence ao calculated in the special case of a very thick layer, allowed the correlation of the experimental data for α _o with those for the porosity of the material on the assumption of a certain geometrical model of the pores, in order to establish the most representative model for the sound absorption phenomenon.