1. A method 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, via a processor, a sample similarity from the plurality of speech samples; making a decision, via the processor, 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.