6. The method as defined in claim 5 wherein if the probability score exceeds a predetermined percentage, the method further comprises switching the base acoustic model with the at least one supplemental acoustic model.
5. The method as defined in claim 4 wherein the co-articulation problem related to the at least two potentially co-articulated tokens in the digit string is detected, and wherein the method further comprises: converting acoustic energy of the utterance into a digital bit pattern; and comparing the digital bit pattern of the utterance with patterns included in the at least one supplemental acoustic model; and generating a probability score based on the comparison.