8. A system comprising: a processor; and a computer-readable storage medium having instructions stored which, when executed by the processor, result in the processor performing operations comprising: receiving, from a user of a speech verification system, a plurality of speech samples of a same word, wherein the plurality of speech samples of the same word comprise: a current speech response; and a plurality of previously recorded speech samples, wherein each of the previously recorded speech samples is associated with a distinct location; generating a sample similarity from the plurality of speech samples; making a decision whether to enroll the user in the speech verification system according to a comparison of the sample similarity with a threshold, wherein the decision is a first decision if the sample similarity is above the threshold and the decision is a second decision different from and mutually exclusive with the first decision if the sample similarity is below the threshold; and enrolling the user in the speech verification system responsively to the decision's being the second decision.
8. A system comprising: a processor; and a computer-readable storage medium having instructions stored which, when executed by the processor, result in the processor performing operations comprising: receiving, from a user of a speech verification system, a plurality of speech samples of a same word, wherein the plurality of speech samples of the same word comprise: a current speech response; and a plurality of previously recorded speech samples, wherein each of the previously recorded speech samples is associated with a distinct location; generating a sample similarity from the plurality of speech samples; making a decision whether to enroll the user in the speech verification system according to a comparison of the sample similarity with a threshold, wherein the decision is a first decision if the sample similarity is above the threshold and the decision is a second decision different from and mutually exclusive with the first decision if the sample similarity is below the threshold; and enrolling the user in the speech verification system responsively to the decision's being the second decision. 11. The system of claim 8 , wherein the speech verification system provides access to a restricted location.