  Inelastic neutron-scattering experiments have been carried out on
polycrystalline samples of the FeSe$_{1-x}$ superconductors. We report the
phonon density of states for FeSe$_{1-x}$ with Tc$\approx$8 K. The phonon
cutoff frequency is observed around 40 meV. No significant change is observed
across the superconducting transition. The measurements support the published
first-principles calculations [A. Subedi et al., Phys. Rev. B \textbf{78},
134514 (2008)].
