Computer Models of Speech Using Fuzzy Algorithms

Recent advances in automatic speech recognition

A knowledge graph based speech interface for question answering systems

A fully integrated speech recognition LSI has been developed. The speech recognition LSI can recognize a speaker-dependent vocabulary of about 200 isolated words with high accuracy in real time, using several memories, which are a phoneme template memory, word dictionary memory, and work memory. This LSI is designed to perform the total speech recognition processing, including the endpoint detection of the input utterance in a self-contained manner. With the pipelined structure of the function blocks, highly efficient parallel operations are achieved. Furthermore, satisfactory testability is assured with a scan path technique. The speech recognition LSI is fabricated with 2 /spl mu/m E/D NMOS process technology, employing two aluminium interconnection layers and a high resistivity poly-Si layer.

A single-chip self-contained speech recognizer

A new recognition algorithm for continuously spoken Japanese is proposed. Recognition is accomplished by finding an optimal syllable sequence using dynamic programming (DP) to avoid the segmentation problem. CV (consonant-vowel) and VCV (vowel-consonant-vowel) templates are used to deal with the co-articulation problem. The VCV templates are prepared only for a subset of vowel and consonant combinations, as a description of the vowel-to-consonant transition, to reduce template registration labor as well as computational requirements. Template matching is made on a VCV level, also using dynamic programming, by connecting the VC part of the VCV template and the whole CV template. A 87% syllable recognition score was obtained for a male speaker. As an application example, large vocabulary word recognition was made. A 93% word recognition score was obtained for a 4300 word vocabulary.

Segmentation-free syllable recognition in continuously spoken Japanese

The speech recognition system composing a part of the question-answering system operated by conversational speech is described. The recognition system consists of two stages of process : acoustic processing stage and linguistic processing stage. In the acoustic processing stage, input speech is analyzed and transformed into the phoneme sequence which usually contains ambiguities and errors caused in the segmentation and phoneme recognition. In the linguistic processing stage, the phoneme sequence containing ambiguities and errors is converted into the correct word sequence by the use of the linguistic knowledge such as phoneme rewriting rules, lexicon, syntax, semantics and pragmatics. The voice-operated question-answering system for seat reservation is constructed by computer simulation technique and the promising results are obtained.

R. Nakatsu

Papers

Speech recognition in the question-answering system operated by conversational speech