STATISTICAL LANGUAGE MODEL GENERATING DEVICE, SPEECH RECOGNITION DEVICE, INFORMATION RETRIEVAL PROCESSOR AND KANA/KANJI CONVERTER

摘要

PROBLEM TO BE SOLVED: To generate a statistical language model capable of enhancing the precision of speech recognition with respect to an unregistered word in a word dictionary and identifying the domain and class of the unregistered word. SOLUTION: An unregistered word model generating section 20 assures that the ratio of the number of words to a mora length in learning data is practically defined as a gamma distribution and estimates and computes the parameters of the gamma distribution of mora lengths while depending on classes, computes the appearance probability of first N-gram which has the class that is a low- order class of a proper noun or a common noun of an adopted word in a subword unit that is mora or a mora link and generates a subword unit N-gram model which is made by modeling word series including unregistered words. A language model generating section 24 generates a statistical language model including unregistered words based on the subword unit based on the word class N-gram model and the subword unit N-gram model and the parameters of a gamma distribution of a mora length.