Method and apparatus for recognizing spoken words in a speech signal by organizing the vocabulary in the form of a tree

US5995930A · kind A · utility

Assignee

• U.S. Philips Corporation · US

Inventors

• Reinhold Hab-Umbach · Aachen, DE
• Hermann Ney · Hamburg, DE

Key dates

• Filing date: Nov 19, 1996
• Grant date: Nov 30, 1999
• Expiry date: Nov 19, 2016

Classification

• Technology area (CPC G): Physics
• CPC primary: G10L15/08
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

A method and apparatus for processing a sequence of words in a speech signal for speech recognition. The method includes the steps of sampling, at recurrent instants, said speech signal for generating a series of test signals. Signal-by-signal matching and scoring is generated between the test signals and a series of reference signals, where each of the series of reference signals forms one of a plurality of vocabulary words arranged as a vocabulary tree. The vocabulary tree includes a root and a plurality of tree branches wherein any tree branch has a predetermined number of reference signals and is assigned to a speech element and any vocabulary word is assigned to a particular branch junction or branch end. Acoustic recombination determines both continuations of branches and the most probable partial hypotheses within a word because of the use of a vocabulary built up as a tree with branches having reference signals. At least one complete word for a particular test signal is determined, and, separately, for each completed word, there is: I) a word result formed including a word score and an aggregate score, said aggregate score derived from said word score and from a language mo…