The inelastic neutron scattering (INS) spectra from 20 to 4000 cm(-1) of various polypyrroles and their ring-deuterated analogues at 30 K shed light on the proton dynamics in these materials. The doped samples obtained by mild oxidation in the presence of FeCl3 in acidic solution were either dedoped in alkaline solution or reduced with TiCl3. The spectra give a continuum with constant intensity due to the recoil of free protons. Virtually all protons are free in the dedoped polymer. Additional protons in the doped and reduced polymers are bound.