Patent Document ID: 5528728
Application ID: 08089825

Base Claim:
1. A speaker independent apparatus for word recognition comprising: a) input means for inputting an utterance by an unspecified person into an electrical signal; b) characteristic extracting means for receiving the electrical signal from the input means and converting the electrical signal into a time series of discrete characteristic multidimensional vectors; c) phoneme recognition means for selectively receiving the time series of discrete characteristic multidimensional vectors and converting each of said selectively received vectors into a plurality of candidates of phonemes from a first order to an n-th order (n denotes an arbitrary number); d) word recognition means for receiving a time series string of phonemes from the phoneme recognition means and comparing the plurality of candidates of phonemes, one at a time, with each phoneme of a reference string of phonemes for words previously stored in a dictionary until a final phoneme of the reference string of phonemes for a last word of the words stored in the dictionary and determining a time series of phonemes derived from said phoneme recognition means having a highest similarity to one of the reference strings of the phonemes for the words stored in the dictionary using a predetermined word matching technique; e) output means for outputting at least one of said candidates of phonemes as a result of word recognition carried out by the word recognition means on the basis of a similarity determination on the plurality of candidates of phonemes with respect to the reference strings of the words stored in said dictionary; and f) selecting means, interposed between said characteristic extracting means and phoneme recognition means, for selecting a center of a given number of frames of a continued time-series of discrete characteristic multidimensional vectors derived from said characteristic extracting means so that said phoneme recognition means receives the center thereof.

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Claim 9:
9. An apparatus as set forth in claim 1, wherein in said predetermined word matching technique, of said word recognition means, a number of branches S{I}{J} is determined under such a condition that (1) two branches are not intersected across each other and (2) only one branch can be drawn from each of phonemes when one of the plurality of the phonemes derived from the phoneme recognition means is compared with one of the reference strings of phonemes for the respective words in such a way as: if A {i}=B {j}, S{i}{j}=S {i-1} {j-1}+1 else S {i}{j}=max (S{i-1}{j}, S{i}{j-1}), wherein A {i}denotes either of the string of phonemes A {i}: i=1 to I derived from the phoneme recognition means or retrieved from the dictionary and B{j} denotes the other string of phonemes to be compared B{j}: j=1 to J and a maximum number of branches N is derived from among S {I}{J} and a magnitude of similarity is derived as N/LA+N/LB, wherein LA denotes a length of the string of phonemes A{i}: i=1 to I and LB denotes a length of the string of phonemes B{j}: j=1 to J, the magnitude of similarity being derived until a final order of candidates from the phoneme recognition means is compared with a final reference string of the word stored in a memory area of the dictionary.