18. A computer readable medium having instructions stored thereon that, when executed, cause a machine to: determine whether a speaker is male; when the speaker is male, use a male variance vector to determine a weighted Euclidean distance between each of a plurality of test utterances and a plurality of training utterances; form a preliminary verification decision for each of the plurality of test utterances to form a plurality of preliminary verification decisions; combine the plurality of preliminary verification decisions to form a verification decision; and weight each of the plurality of preliminary verification decisions based on a historical error rate corresponding to a respective one of the test utterances.
18. A computer readable medium having instructions stored thereon that, when executed, cause a machine to: determine whether a speaker is male; when the speaker is male, use a male variance vector to determine a weighted Euclidean distance between each of a plurality of test utterances and a plurality of training utterances; form a preliminary verification decision for each of the plurality of test utterances to form a plurality of preliminary verification decisions; combine the plurality of preliminary verification decisions to form a verification decision; and weight each of the plurality of preliminary verification decisions based on a historical error rate corresponding to a respective one of the test utterances. 21. The computer readable medium of claim 18 having instructions stored thereon that, when executed, cause the machine to: receive a plurality of input utterances; segment the plurality of input utterances into voiced sounds and unvoiced sounds; and extract features from the voiced sounds to form the plurality of test utterances.