11. A method of automatic speech recognition, comprising the steps of: (a) receiving an utterance from a user via a microphone that converts the utterance into a speech signal; (b) pre-processing the speech signal using a processor to extract acoustic data from the received speech signal; (c) identifying at least one user-specific characteristic including pitch and at least one formant in response to the extracted acoustic data; (d) determining a user-specific confidence threshold responsive to the identified at least one user-specific characteristics, wherein the determination comprises using a multiple regression calculation including the identified user-specific pitch and at least one formant and a pitch coefficient and at least one formant coefficient developed from a plurality of development speakers; and (e) decoding the acoustic data based on the user-specific confidence threshold to produce a plurality of hypotheses for the received utterance, including calculating confidence scores for the hypotheses.
12. The method of claim 11 , further comprising the step of: (f) post-processing the plurality of hypotheses, including using the user-specific confidence threshold to identify at least one hypothesis of the plurality of hypotheses as the received utterance, wherein the user-specific confidence threshold is a recognition confidence threshold.