Within mean field theory we reexamine the collective modes associated
with the phase fluctuation in the presence of long range Coulomb inter
action. We find that the phason propagator is dominated by an acoustic
mode and an optical mode. These modes have already been described by
Nakane and Takada and Wong and Takada. However, due to their inconsist
ent approximations, their results became unreliable; particularly in t
he vicinity of the transition temperature. Relevance of these modes to
those found in the Raman and neutron scattering from blue bronze is b
riefly discussed.