12. A system, comprising: an audio pick up device for capturing a speech sample from a claimant claiming a computer readable medium; and a central processing unit interacting with the computer readable medium to perform the following steps: a component, implemented in a computer, capable of: calculating a ratio of unvoiced frames to a total number of frames in the speech sample, determining an equal error rate value corresponding to the speech sample based on the calculated ratio, comparing the determined equal error rate value corresponding to the speech sample to an equal error rate value associated with the claimed identity to select a decision threshold, generating a match score based on a comparison of the speech sample to a voice sample associated with the claimed identity, and deciding whether to accept the identity claim of the claimant based on a comparison of the match score to the decision threshold.
12. A system, comprising: an audio pick up device for capturing a speech sample from a claimant claiming a computer readable medium; and a central processing unit interacting with the computer readable medium to perform the following steps: a component, implemented in a computer, capable of: calculating a ratio of unvoiced frames to a total number of frames in the speech sample, determining an equal error rate value corresponding to the speech sample based on the calculated ratio, comparing the determined equal error rate value corresponding to the speech sample to an equal error rate value associated with the claimed identity to select a decision threshold, generating a match score based on a comparison of the speech sample to a voice sample associated with the claimed identity, and deciding whether to accept the identity claim of the claimant based on a comparison of the match score to the decision threshold. 13. The system of claim 12 , wherein the determining of the equal error rate value corresponding to the speech sample includes using a function that describes a relationship between equal error rate values and ratios of unvoiced frames to a total number of frames in a population.