Recognizing speech data using a state transition model

A recognition method for recognizing speech data by comparing an unknown word in speech data with data of known words without learning a model for recognition, comprising:

• an obtaining step of obtaining a state having the maximum likelihood for each part of the speech data, from plural states employed in a state transition model for known words, to be employed in speech recognition of known words;
• an ergodic model preparation step of preparing an ergodic model of an unknown word from the obtained states having the maximum likelihood, the obtained states being numbered in a description inserted in a portion where a processing for the unknown word is desired in a recognition grammar;
• a calculation step of calculating a likelihood for an unknown word in the speech data by multiplying the maximum likelihood of each state by a transition probability for the entire transitions in unknown words;
• and
• a recognition step of effecting recognition of said speech data based on the likelihood calculated by the calculation means.

A computer controlled apparatus for effecting a speech recognition process by reading a predetermined program from a memory medium and comparing an unknown word in speech data with data of known words without learning a model for recognition, wherein said memory medium comprises:

• a first process code for causing the computer controlled apparatus to obtain a state having maximum likelihood for each part of the speech data, from plural states employed in a state transition model for known words, to be employed in speech recognition of known words;
• a second process code for causing the computer controlled apparatus to prepare an unknown word from the obtained states having the maximum likelihood, the obtained states being numbered in a description inserted in a portion where a processing for the unknown word is desired in a recognition grammar;
• a third process code for causing the computer controlled apparatus to calculate a likelihood for an unknown word in the speech data by multiplying the maximum likelihood of each state by a transition probability commonly used for the entire transition in unknown words;
• and
• a fourth process code for causing the computer controlled apparatus to effect recognition of said speech data based on the likelihood calculated by the calculation means.