  We argue that neutron spectra in a short-range ordered Valence Bond state is
dominated by two-spinon states localized in small spatial regions such as a
pinwheel. These excitations lead to angle averaged dynamic structure factor
that is spread over a wide frequency range up to about $2.5 J$, whereas its
wavevector dependence at all frequencies remains very close to that of isolated
dimers. These results are in excellent agreement with recent Neutron scattering
data in the Herbertsmithite materials ZnCu$_3$(OH)$_6$Cl$_2$.
