Dipole reorientation under the influence of an electric field is investigated in oriented nylon 11 films with polarized infrared spectroscopy for the amide A and amide I bands. Butterfly-shaped hysteresis loops are obtained from peak intensity versus applied electric field strength. Least-squares Gaussian curve fitting of the resolved multiple contributions to the amide I peak show that the components change in either a continuously reducing S-shaped fashion, or in butterfly-shaped curves under ac poling fields. Time-dependent studies of the absorption intensities show that both ordered and disordered species switch towards the electric field direction with the application of electric fields higher than the coercive field. Upon field removal, only the disordered species show orientation relaxation away from the field direction. Below the coercive field, neither species responds orientationally to the field.