1. A semiconductor integrated circuit device comprising: a signal processing unit which performs Fourier transform on an inputted voice signal, thus extracts frequency components of the voice signal, and generates a feature pattern representing a state of distribution of the frequency components of the voice signal; a voice recognition database storage unit which stores a voice recognition database including a standard pattern representing a state of distribution of frequency components of plural phonemes used in a predetermined language; a conversion list storage unit which stores a conversion list expressed by character data and including plural words or sentences to be conversion candidates; a standard pattern extraction unit which extracts the standard pattern corresponding to the character data representing the first syllable of each word or sentence included in the conversion list, from the voice recognition database; and a matching detection unit which compares the feature pattern generated from the first syllable of the voice signal with the standard pattern extracted by the standard pattern extraction unit, thus detects the matching of the syllable, and outputs information specifying a word or sentence that has the matching-detected syllable as the first syllable thereof.