4. The method of claim 1 , further comprising an act of segmenting the voice signal into a plurality of frames, each of the plurality of frames corresponding to a respective interval of the voice signal, and wherein the acts of: detecting a plurality of candidate features includes an act of detecting a plurality of candidate features in each of the plurality of frames; and grouping the plurality of candidate features includes an act of grouping different combinations of the plurality of candidate features detected in each of the plurality of frames into a respective plurality of candidate feature sets, each of the plurality of candidate feature sets associated with one of the plurality of frames from which the corresponding plurality of candidates features was detected, and further grouping different combinations of the plurality of candidate feature sets to form a respective plurality of candidate feature tracts.
4. The method of claim 1 , further comprising an act of segmenting the voice signal into a plurality of frames, each of the plurality of frames corresponding to a respective interval of the voice signal, and wherein the acts of: detecting a plurality of candidate features includes an act of detecting a plurality of candidate features in each of the plurality of frames; and grouping the plurality of candidate features includes an act of grouping different combinations of the plurality of candidate features detected in each of the plurality of frames into a respective plurality of candidate feature sets, each of the plurality of candidate feature sets associated with one of the plurality of frames from which the corresponding plurality of candidates features was detected, and further grouping different combinations of the plurality of candidate feature sets to form a respective plurality of candidate feature tracts. 6. The method of claim 4 , wherein each of the plurality of feature tracts includes an associated candidate feature set from each of the plurality of frames.