Stressed Syllable Determination for Romanian Words within Speech Synthesis Applications

This paper proposes and experimentally evaluates a method to determine the stressed syllable of a word in the framework of speech synthesis in Romanian. In order to produce high quality speech, a speech synthesis system needs information about the position of the stress for each word of a sentence to be generated. Otherwise, incorrect positioning of stress (or, in the worst case, completely ignoring it) translates into poor quality synthesized speech. Since Romanian is a free-stressed language (as is English, for example), the position of the stressed syllable within a word is not clearly defined. Consequently, a set of explicit rules that can determine the exact position of the stress is difficult to generate. In order to solve this problem, we propose an original method to find stressing rules for the Romanian language as well as an algorithm to implement this method. According to this algorithm, the position of the stressed syllable is computed according to a number of word parameters encompassing morphologic, phonetic, and lexical characteristics of the word. The experimental results show that the errors of the automatic stress assignment using our method do not exceed 6%.