A sound barrier is a structure or device that reduces the level of airborne sound. The basic tasks of such a construction are to provide acoustic insulation and sound absorption. There are many materials available on the market ready to use as such structures used for soundproofing passenger vehicles, construction machinery, power units, etc. In this case, however, the practical use of ready-made materials for minimizing noise requires the use of barriers more complicated in construction than those made of a single material. Thus, each time it is necessary to adjust acoustic parameters of barrier to the individual characteristics of equipment whose acoustic emission we want to reduce. Tests according to standards of such structures require work- and time-consuming and expensive research, e.g. special rooms are required for do this (reverberation and anechoic chambers), which are not always available. In this paper, the author proposes a comparative measurement using a simplified method, which can be used in industrial conditions or small measurement laboratories.