A method for hierarchical analysis of electronic circuits comprises selecting a first one of a plurality of abstraction levels of a general design model. The earth separating member is a hollow, triangular body formed by opposing triangular plates maintained in spaced apart relation by edge plates around the periphery. The vibration detector has a tubular inner part provided, which is dimensioned such that it is positioned between the housing wall and a drivereceiving unit, and that the tubular inner part is connected to the housing or to the diaphragm.