Construction of corpus-based syntactic rules for accurate speech recognition

This paper describes the syntactic rules which are applied in the Japanese speech recognition module of a speech-to-speech translation system. Japanese is considered to be a free word/phrase order language. Since syntactic rules are applied ms constraints to reduce the search space in speech recognition, applying rules which take into account all possible pitrase orders can have almost the same effect as using no constraints. Instead, we take into consideration the recognition weaknesses of certain syntactic categories and treat them precisely, so that a minimal number of rules can work most effectively. In this paper we first examine which syntactic categories are easily misrecognized. Second, we consult our dialogue corpus, in order to provide the rules with great generality. Based on both studies, we refine tile rules. Finally, we verify the validity of the refinement through speech recognition experiments

Precise measurement method of a speech translation system’s capability with a paired comparison

The main goal of the present paper is to propose new schemes for the overall evaluation of a speech translation system. These schemes are expected to support and improve the design of the target application system, and precisely determine its performance. Experiments are conducted on the Japanese-to-English speech translation system ATR-MATRIX, which was developed at ATR Interpreting Telecommunications Research Laboratories. In the proposed schemes, the system’s translations are compared with those of a native Japanese taking the Test of English for International Communication (TOEIC), which is used as a measure of one’s speech translation capability. Subjective and automatic comparisons are made and the results are compared. A regression analysis on the subjective results shows that the speech translation capability of ATR-MATRIX matches a Japanese person scoring around 500 on the TOEIC. The automatic comparisons also show promising results