Example embodiments provide a speaker authentication technology that compensates for mismatches between enrollment process conditions and test process conditions using correction parameters or correction models, which allow for correcting one of the test voice characterizing parameter set and the enrollment voice characterizing parameter set according to a mismatch between the test process conditions and the enrollment process conditions, thereby obtaining values for the test voice characterizing parameter set and the enrollment voice characterizing parameter set that are based on the same or at least similar process conditions. Alternatively, each of the enrollment and test voice characterizing parameter sets may be normalized to predetermined standard process conditions by using the correction parameters or correction models.