  We have performed polarized Raman scattering measurements on the newly
discovered superconductor Ba$_{2}$Ti$_{2}$Fe$_{2}$As$_{4}$O$_{2}$ ($T_c = 21$
K). We observe seven out of eight Raman active modes, with frequencies in good
accordance with first-principle calculations. The phonon spectra suggest
neither strong electron-phonon nor spin-phonon coupling and vary only slightly
with temperature, except for one E$_g$ mode associated with large displacements
of As atoms near the Ti$_2$O planes. We also identify a small anomaly around
125 K in the linewidth of a A$_{1g}$ mode involving the same As atoms. Our
results suggest that the transition at 125 K is most likely driven by
electronic interactions taking place in the Ti$_2$O planes.
