We have measured the mean charged particle multiplicity separately
for heavy and light quark initiated events produced in e$^+$e$^-$
annihilations at LEP. In particular, we have determined the energy
dependence of their difference, for which theoretical predictions
exist. Perturbative QCD calculations in the MLL approximation with
the assumption of Local Parton Hadron Duality predict this difference 
to be energy independent, due to the combination of gluon coherence and 
quark-mass effects. In constrast, a more phenomenological 
na\"{\i}ve model,
which assumes that the multiplicity accompanying the decay of a heavy 
quark is independent of the quark mass itself, predicts a difference
which decreases with energy. The data, recorded with the OPAL detector
above the Z0 peak between 130 and 206 GeV, are compared with the 
predictions of the two models.