  We present a Raman scattering study of Ca$_2$RuO$_4$, in which we investigate
the temperature-dependence of the lattice dynamics and the electron-phonon
interaction below the metal-insulator transition temperature ({\it T}$_{\rm
MI}$). Raman spectra obtained in a backscattering geometry with light polarized
in the ab-plane reveal 9 B$_{1g}$ phonon modes (140, 215, 265, 269, 292, 388,
459, 534, and 683 cm$^{-1}$) and 9 A$_g$ phonon modes (126, 192, 204, 251, 304,
322, 356, 395, and 607 cm$^{-1}$) for the orthorhombic crystal structure
(Pbca$-$D$_{2h}^{15}$). With increasing temperature toward {\it T}$_{\rm MI}$,
the observed phonon modes shift to lower energies and exhibit reduced spectral
weights, reflecting structural changes associated with the elongation of the
RuO$_6$ octahedra. Interestingly, the phonons exhibit significant increases in
linewidths and asymmetries for {\it T} $>$ {\it T}$_{\rm N}$. These results
indicate that there is an increase in the effective number of electrons and the
electron-phonon interaction strengths as the temperature is raised through {\it
T}$_{\rm N}$, suggesting the presence of orbital fluctuations in the
temperature regime {\it T}$_{\rm N}$ $<$ {\it T} $<$ {\it T}$_{\rm MI}$.
