A theoretical method for treating the effects of liquid dynamics on vibrational band profiles is developed for the situation where resonant intermolecular vibrational interactions are operating. The liquid dynamics is simulated by the molecular dynamics (MID) technique, and the coupled vibrational Hamiltonian is constructed at each time step of the MID runs. Time evolution of delocalized IR and Raman excitations caused by this time-dependent coupled vibrational Hamiltonian is calculated to obtain IR and Raman band profiles as the Fourier transform of the corresponding time correlation functions. This method is applied to the case of the C=O stretching band of neat liquid acetone, a typical case where the effect of resonant intermolecular vibrational interactions is known to be significant. The noncoincidence effect observed in this band is well reproduced. In addition, a better agreement between the observed and calculated bandwidths is obtained by using the present method as compared to the result of the calculation using only static liquid structures. As such, the present method is suggested to be a useful one for treating the effects of liquid dynamics on vibrational band profiles when the vibrations are resonantly coupled. The time scale of the modulation of vibrational eigenstates caused by the liquid dynamics is also discussed.