Patent Document ID: 4336421
Application ID: 06138643

Base Claim:
1. Apparatus for receiving input spoken vocabulary words during a training phase of operation and for subsequently recognizing strings of received input spoken command words, comprising: feature extraction means for generating digital feature signals dependent on the features present in input words; reference array formation means for forming and storing, for each vocabulary word, a time-dependent reference array dependent on the feature signals present during the vocabulary word as spoken during the training phase; boundary detection means for detecting relatively long duration pauses between speech sounds as inter-string pauses from which string boundaries are determined, the string boundaries defining the beginning and end of a string of words, and for detecting relatively short duration pauses between speech sounds as inter-segment pauses from which speech segment boundaries are determined within a string of words; candidate feature array formation means for forming and storing, for each command word candidate consisting of each segment and each sequence of up to a predetermined number of segments, a time-dependent candidate feature array dependent upon the feature signals present during said command word candidate; array correlation means for comparing each candidate feature array with each reference array and for storing, for each command word candidate, the vocabulary word whose reference array results in the highest correlation and a record of the score of said highest correlation; string matching means responsive to the stored correlation scores for determining the sequence of vocabulary words that yields the highest overall correlation score for the string; and means for generating output indications of the determined sequence of vocabulary words.

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Claim 3:
3. Apparatus as defined by claim 1 wherein said candidate feature array formation means is operative to form a candidate feature array for each of the following: a command word candidate consisting of each individual speech segment considered as a one segment word; a command word candidate consisting of each individual speech segment together with the previous speech segment, if any, considered as a two segment word; a command word candidate consisting of each individual speech segment together with the previous two speech segments, if any, considered as a three segment word; and a command word candidate consisting of each individual speech segment together with the previous three speech segments, if any, considered as a four segment word.