The presence of high level of acoustic load especially in urban areas is becoming a serious problem in the present. In order to protect people against adverse effects of audio noise on health and personal well-being in buildings located in such areas, convenient construction materials with sophisticated geometric arrangement should be used. Bearing structures of new houses in the Czech Republic are widely made of different types of brick blocks. Such brick blocks consist of solid matrix and cavities designed in an optimized geometrical way in order to assure better thermal and hygric properties. Previous studies dealing both with acoustic properties in an empirical way and with the theoretical aspects of acoustic attenuation in building materials were not very numerous. Nevertheless, they gain constantly in importance with increasing acoustic load of the buildings surroundings. In this paper, a theoretical approach for the determination of acoustic properties, which is convenient for the description of sound waves propagation in building materials, is introduced.