A STUDY OF THE SOUND REFLECTION FROM POROUS MATERIAL BY IMPULSE METHOD

This paper presents a study of the reflection of sound pulse from porous material in the ease that the impulse sound source and receiver are located on a line perpendicular to the surface of material. The transfer functions of reflected sound wave were calculated from the experimental incident and the reflected sound pulses by use of DPT. The impulse response of reflected sound wave am be calculated theoretically under the assumption of idealized porous material. Both local reaction and extended reaction of the material were taken in the calculations. A comparison of the calculations for spherical wave and plane wave provides a measure of the effect of spherical wave on the transfer function of reflected sound wave. For a layer of porous material the reflections in the material are studied.