We consider a mathematical model of acoustics in heterogeneous medium with two different components with the common boundary. One of these is a bounded liquid domain and the other is a poroelastic medium. Poroelastic medium is perforated by pores. A pore space is filled with a viscous liquid. The motion of the liquid and the joint motion of the poroelastic media with porous space are governed by the differential equations based on the continuum mechanics laws. These equations contain rapidly oscillating terms, depending on the small parameter.
