Semi-Automatic Learning of Acoustic Models

of Patent 4783803) A system is disclosed for recognizing a pattern in a collection of data given a context of one or more other patterns previously identified. Preferably the system is a speech recognition system, the patterns are words and the collection of data is a sequence of acoustic frames. During the processing of each of a plurality of frames, for each word in an active vocabulary, the system updates a likelihood score representing a probability of a match between the word and the frame, combines a language model score based on one or more previously recognized words with that likelihood score, and prunes the word from the active vocabulary if the combined score is below a threshold. A rapid match is made between the frames and each word of an initial vocabulary to determine which words should originally be placed in the active vocabulary. Preferably the system enables an operator to confirm the system's best guess as to the spoken word merely by speaking another word, to indicate that... This patent is only one example. There are several patents from the same era showing different methods for doing a fast match. Thus fast match is a well-proven technique in speech recognition even though it has not been widely discussed in the research literature. Normally the scores computed by the fast match, if any, are used only internally in the fast match. That is, once the vocabulary subset has been selected, new scores are