An alcohol consumption determination method includes: detecting an effective frame of an input voice signal; detecting a difference signal of an original signal of the effective frame; performing fast Fourier conversion on the original signal and the difference signal; and determining, in the frequency domain, whether alcohol has been consumed based on a slope difference between the fast-Fourier-transformed original signal and the fast-Fourier-transformed difference signal. Accordingly, it is also possible to determine whether a driver or an operator from a remote location has consumed alcohol and a degree of the consumption, thus preventing an accident caused by an individual operating a vehicle under the influence.