Acoustic correlates of Dutch lexical stress re-examined: Spectral tilt is not always more reliable than intensity

Abstract

The present study examined two acoustic cues in the production of lexical stress in Dutch: spectral tilt and overall intensity. Sluijter and Van Heuven (1996) reported that spectral tilt is a more reliable cue to stress than intensity. However, that study included only a small number of talkers (10) and only syllables with the vowels /aː/ and /ɔ/. The present study re-examined this issue in a larger and more variable dataset. We recorded 38 native speakers of Dutch (20 females) producing 744 tokens of Dutch segmentally overlapping words (e.g., VOORnaam vs. voorNAAM, “first name” vs. “respectable”), targeting 10 different vowels, in variable sentence contexts. For each syllable, we measured overall intensity and spectral tilt following Sluijter and Van Heuven (1996). Results from Linear Discriminant Analyses showed that, for the vowel /aː/ alone, spectral tilt showed an advantage over intensity, as evidenced by higher stressed/unstressed syllable classification accuracy scores for spectral tilt. However, when all vowels were included in the analysis, the advantage disappeared. These findings confirm that spectral tilt plays a larger role in signaling stress in Dutch /aː/ but show that, for a larger sample of Dutch vowels, overall intensity and spectral tilt are equally important.