Effects of pitch range variation on f0 extrema in an imitation task

Abstract

A central issue in speech intonation research concerns how fundamental frequency ( f 0) variation relates to phonological categories. The hypothesis was tested that pitch range variation which affects whether one syllable is higher or lower than another would elicit categorical shifts in f 0 extremum timing in an imitation task. Participants heard synthetic versions of the phrase Some lemonade with rising-falling or falling-rising intonation and flat f 0 contours across le- and mo-. The f 0 levels of le- and mo- were varied such that for half the stimuli, le- had a higher f 0 than mo-, while the reverse was true for the remainder. Participants produced f 0 peaks and valleys on syllables that had flat f 0 in stimuli; extremum types (peaks or valleys) and their temporal alignments varied categorically with the relative f 0 levels of le- and mo- in the stimuli. The results are discussed in terms of theories of intonational phonology. It is shown that an account of these results under autosegmental-metrical theory (e.g., Pierrehumbert, J. (1980). The phonology and phonetics of English intonation. Ph.D. dissertation, MIT, Cambridge, MA) requires positing additional constraints in phonetic models of f 0. A revised version of the Pierrehumbert and Beckman [(1988). Japanese tone structure. Cambridge, MA: MIT Press] phonetic model is therefore proposed which assumes additional constraints on relative tone heights and strictly monotonic interpolation between tones.