Method of verifying a speaker

An improved method of verifying the speaker from whom long term spectral characteristics have been derived during a learning phase. Mean values and distance thresholds have been calculated and stored. Improved recognition is obtained by incorporating into the stored values additional values of speech samples in ranges situated outside the distance threshold value. When, during verification, a speech sample not situated within the distance threshold value is encountered its distance from the additionally stored speech samples is successively determined and compared with the separate distance threshold value. The speaker is rejected only if the speech sample to be verified is not situated at a sufficiently small distance from any of the additionally stored speech samples. The method thus increases the recognition range to better approximate the actual distribution of speech samples of the learning phase.