6. A circuit for recognizing an unknown utterance as one of a set of reference words according to claim 5 wherein said means for producing a signal representative of the distance between said unknown utterance prediction parameter signals and said template prediction parameter signals is further characterized in that means (205) are responsive to the unknown utterance to determine the number of frames to the endpoint frame of said unknown utterance; means (880, 1806) are adapted to generate a first signal corresponding to the average frame distance between the unknown utterance prediction parameter signals and said template signal prediction parameter signals until said endpoint frame, to determine the unknown utterance intermediate frame at which the unknown utterance speech signal energy from said intermediate frame to said endpoint frame is a predetermined portion of the total unknown utterance speech signal energy, and to generate a second signal corresponding to the average frame distance between said unknown utterance prediction parameter signals and said template prediction parameter signals until said intermediate frame; and means (1817, 1820) are responsive to said first and second signals to select the minimum of said first and second signals as said distance representative signal.
6. A circuit for recognizing an unknown utterance as one of a set of reference words according to claim 5 wherein said means for producing a signal representative of the distance between said unknown utterance prediction parameter signals and said template prediction parameter signals is further characterized in that means (205) are responsive to the unknown utterance to determine the number of frames to the endpoint frame of said unknown utterance; means (880, 1806) are adapted to generate a first signal corresponding to the average frame distance between the unknown utterance prediction parameter signals and said template signal prediction parameter signals until said endpoint frame, to determine the unknown utterance intermediate frame at which the unknown utterance speech signal energy from said intermediate frame to said endpoint frame is a predetermined portion of the total unknown utterance speech signal energy, and to generate a second signal corresponding to the average frame distance between said unknown utterance prediction parameter signals and said template prediction parameter signals until said intermediate frame; and means (1817, 1820) are responsive to said first and second signals to select the minimum of said first and second signals as said distance representative signal. 7. A circuit for recognizing an unknown utterance as one of a set of reference words according to claim 6 wherein said distance signal generating and storing means comprises means for storing the distance signals for each reference word in a storage matrix of J rows and J columns; and said centermost set determining means is characterized by means (702-1 through 702-J) responsive to the distance signals of each column of said matrix for selecting the maximum distance signal of said column; means (720) responsive to said selected maximum distance signals for determining the minimum of said selected maximum distance signals; and means (228, 230 for storing the row position of said determined minimum of the selected maximum distance signals to identify the centermost set.