Acoustic correlates of stress and their use in diagnosing syllable fusion in Tongan.

Abstract

The first goal of this study is to determine which acoustic cues correlate with stress in Tongan. Preliminary data indicate that pitch (F0), duration, and vowel height (F1) are the best cues to stress. Differences are also found for vowel frontness (F2), intensity, and voice quality. The second goal is to use these acoustic stress correlates to test for syllable fusion, an alleged phonological process in Tongan by which sequences of vowels in separate syllables fuse into a single syllable (e.g., Poser 1985). Lower‐to‐higher sequences (e.g., /ai/) are said to undergo fusion while higher‐to‐lower sequences (e.g., /ia/) are not. However, no empirical studies have been conducted testing these claims. Using the acoustic stress cues identified for Tongan, these two types of sequences are compared, where the first vowel of each sequence falls in a stressed position. For higher‐to‐lower sequences (e.g., /ia/), the first vowel should show acoustic cues of stress whereas the second vowel should appear unstressed. For lower‐to‐higher sequences (e.g., /ai/), if syllable fusion occurs, acoustic stress cues should be present over the entire sequence; otherwise, stress cues should be seen only on the first vowel as in nonfusing higher‐to‐lower sequences. Preliminary data indicate that syllable fusion does occur.