Automatic continuous speech recognition system employing dynamic programming

A speech pattern recognition system for continuous speech composed of a series of words pronounced word by word, said system comprising:

• means for producing from said continuous speech an input pattern A representative of time sequences of feature vectors a.sub.1, a.sub.2 - - - a.sub.i, - - - a.sub.I :
• first memory means for storing said input pattern A;
• second memory means for storing n reference word patterns B.sup.n, each representing by time sequences of feature vectors b.sub.1.sup.n, b.sub.2.sup.n, - - -b.sub.j.sup.n, - - - b.sub.jn.sup.n ;
• means for reading out a partial pattern A(l,m) which is a part of said input pattern A extending from a time point l to another time point m (1.ltoreq.l<m.ltoreq.I), said partial pattern A(l,m) being represented by time sequence of feature vectors a.sub.l+1, a.sub.l+2, - - - a.sub.i, - - - a.sub.m ;
• first means for calculating through dynamic programming similarity measures S(A(l,m), B.sup.n) between said partial pattern A(l,m) and said reference word pattern B.sup.n ;
• means for extracting the maximum value of the partial similarity measures S<l,m>
• with respect to n words;
• means for providing a partial recognized result n<l,m>
• which is a word in said n words and by which said partial similarity measure S<l,m>
• is obtained;
• third memory means for said partial similarity measure s<l,m>
• and said partial recognized result n<l,m>
• obtained with respect to said time points l and m;
• means for dividing said input pattern A to Y partial patterns A(l.sub.(x-1), L.sub.(x)) (X = 1, 2, 3, - - - Y), said input pattern A being composed of Y words and having (Y - 1) breaking points l.sub.(1), l.sub.(2) - - - l.sub.(x) - - - l.sub.(Y-1) ;
• means responsive to said partial similarity measure S<l,m>
• and said partial recognized result n<l,m>
• for reading out the partial similarity measures S<O,l.sub.(1) >, S<l.sub.(1),l.sub.(2) >, - - - S<l.sub.(x-1), l.sub.(x) >, - - - S<l.sub.Y-1), l.sub.(Y) >
• with respect to the combinations (O,l.sub.(1)), (l.sub.(1), l.sub.(2)), - - - (l.sub.(x-1), l.sub.(x)), - - - (l.sub.(Y-1), l.sub.(Y)) of said breaking points;
• second means for calculating the maximum value of the sum of said partial similarity measures S>O,l.sub.(1) >+S<l.sub.(1), l.sub.(2) >+- - - + S<l.sub.(x-1), l.sub.(x) >
• - - - + S<l.sub.(Y-1), l.sub.(Y) >;
• and
• means responsive to said second calculating means and said partial recognized result n, m for providing Y words.