ADAPTING INPUT SPEECH AND REFERENCE PATTERNS FOR CHANGING SPEAKER AND ENVIRONMENT

Speech input is converted into a feature vector series, which is held as an input pattern in an input pattern memory and which is also fed to a preliminary recognizer. A reference pattern memory stores reference patterns of recognition subject words. The preliminary recognizer executes preliminary recognition by calculating similarity measures between the input pattern and the reference patterns stored in a reference pattern memory, and obtains top N candidates using the calculated similarity measures. A reference pattern adapter executes adaptation of the reference patterns based on the reference patterns, the input pattern, the top N candidates, and newly stores the adapted reference patterns in the reference pattern memory. A final recognizer then executes speech recognition of the input pattern by using the newly-stored reference patterns corresponding to the top N candidates.