Computational modeling of accent and intonation in declarative sentences of Spanish

Abstract

Although Spanish is commonly known to have stress accent, preliminary study shows that the word accent in Spanish has a clear and consistent manifestation in the voice fundamental frequency contour (henceforth the F0 contour). The present study is aimed at obtaining analytic and quantitative description of the prosodic characteristics of Spanish useful both for basic understanding and for speech synthesis. The speech material consists of a set of 21 declarative sentences of various lengths, designed to examine effects of word accent, syntactic, and discourse structure as well as speaker’s intention. These sentences were read by two native speakers of Castilian Spanish. The F0 contours were extracted by computer and were further analyzed using a quantitative model of the process of F0 contour generation, originally proposed for Japanese [Fujisaki etal., Proc. 7th ICA 3, 133–136 (1971)]. The results indicate that the model applies quite well to F0 contours of Spanish as far as the present material is concerned. An F0 contour can be represented by the sum of phrase components and accent components, the former being correlated to the syntactic structure and the latter to the lexical word accent. Focus is indicated by an increase in the magnitude of the accent component, while speaker’s intention is indicated by the presence of another component occurring toward the end of a phrase or a sentence. These results provide a powerful tool for high-quality text-to-speech synthesis.