Hiroshi Shimura

Speech recognition apparatus using pitch extraction

A speech recognition apparatus includes a dictionary for storing information related to registered speeches for use in making a speech recognition, and a registration part for storing the infromation into the dictionary. The registration part includes a filter bank made up of first through nth filters and supplied with a speech which is to be registered in the dictionary, a first circuit part for generating recognition template information based on an output of the filter bank and for storing the recognition template information in the dictionary, and a second circuit part for generating pitch frequency information based on an output of the filter bank and for storing the pitch frequency information in the dictionary. The pitch frequency information is related to a frequency f which satisfies Min│A(f)│, where ##EQU1## Xj (f) denotes a theoretical filter gain of a jth filter of the filter bank at the frequency f, Gj denotes a filter gain which is observed for the jth filter, and the pitch frequency is defined as a resonant frequency which is a most likely greatest common measure of filter gains of the first through nth filters of the filter bank.