24. An apparatus for determining whether a speaker uttering a tested utterance belongs to a predetermined set comprising an at least one known speaker, wherein an at least one training utterance is available for each of the at least one known speaker, the apparatus comprising: a feature extraction component for extracting a feature group of the tested utterance or of each of the at least one training utterance; a fast scoring component for scoring a part of the feature group associated with part of the tested utterance against an at least one model for obtaining a fast intermediate score, determining an at least one fast model score using the fast intermediate score, and selecting an at least one probable model associated with a fast intermediate score which is higher than other fast intermediate scores; a frame scoring component for scoring the feature group against an at least one probable model, to obtain an at least one intermediate score; a total model scoring component for determining an at least one model score using the at least one intermediate score; and a maximal score determination component for selecting a maximal score from the at least one model score.
24. An apparatus for determining whether a speaker uttering a tested utterance belongs to a predetermined set comprising an at least one known speaker, wherein an at least one training utterance is available for each of the at least one known speaker, the apparatus comprising: a feature extraction component for extracting a feature group of the tested utterance or of each of the at least one training utterance; a fast scoring component for scoring a part of the feature group associated with part of the tested utterance against an at least one model for obtaining a fast intermediate score, determining an at least one fast model score using the fast intermediate score, and selecting an at least one probable model associated with a fast intermediate score which is higher than other fast intermediate scores; a frame scoring component for scoring the feature group against an at least one probable model, to obtain an at least one intermediate score; a total model scoring component for determining an at least one model score using the at least one intermediate score; and a maximal score determination component for selecting a maximal score from the at least one model score. 25. The apparatus of claim 24 further comprising a model estimation component for estimating the at least one model.