  Quasi one-dimensional conductors which undergo a Peierls transition to a
charge density wave state at a temperature T_P show a region of one-dimensional
fluctuations above T_P. The Ginzburg-Landau-Langevin theory for the frequency
dependent collective conductivity from conductive fluctuations into the charge
density wave state is developed. By inclusion of a phase breaking term the
effect of local pinning due to random impurities is simulated. It is found that
the spectral weight of unpinned fluctuations is partly redistributed into a
pinned mode around a pinning frequency in the far infrared region. In addition,
selection rule breaking by the imputities makes the fluctuating amplitude mode
visible in the optical response.
