A device for indicating at least a first vibration level VIB1 derived from a first acceleration signal .gamma.1 includes: first analysis element FT1 for resolving the first acceleration signal .gamma.1 into a plurality of axial analysis signals .gamma.1.sub.i each occupying an identified frequency band B.sub.i; a first memory RM1 having recorded therein a plurality of axial weighting coefficients KA.sub.i, each corresponding to one of the identified frequency bands B.sub.i; and a first control circuit CC for summing the p.sup.th powers of the axial analysis signals .gamma.1.sub.i weighted by the axial weighting coefficients KA.sub.i, thereby producing the first vibration level VIB1.