1. A method, comprising: capturing a speech sample from a claimant claiming an identity; 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.