Techniques for acquiring, from an input text and an input speech, a set of a character string and a pronunciation thereof which should be recognized as a word. A system according to the present invention: selects, from an input text, plural candidate character strings which are candidates to be recognized as a word; generates plural pronunciation candidates of the selected candidate character strings; generates frequency data by combining data in which the generated pronunciation candidates are respectively associated with the character strings; generates recognition data in which character strings respectively indicating plural words contained in the input speech are associated with pronunciations; and selects and outputs a combination contained in the recognition data, out of combinations each consisting of one of the candidate character strings and one of the pronunciation candidates.
Unsupervised lexicon acquisition from speech and text