Pharyngeal constriction in English diphthong production

Abstract

This study tests the hypothesis that the acoustic difference between [a] in English diphthongs (e.g., [a] in “pie’d”) and its corresponding monophthong (e.g., [a] in “pod”) results from the same pharyngeal gesture being truncated by the following palatal glide in the diphthongal environment. Production data were collected with real-time MRI and have been analyzed using the direct image analysis (DIA) technique, which infers tissue movement by tracking pixel intensity change over time in regions of interest. Preliminary results show that (1) DIA is capable of capturing the timing and magnitude of the pharyngeal constriction gesture that produces [a], and (2) the proposed hypothesis is supported; the formation time of the pharyngeal constriction in diphthongs is generally shorter than that in like monophthongs. Further, the pharyngeal component of the diphthong is shortened in phrase-medial as opposed to phrase-final position or when followed by a voiceless as opposed to a voiced coda consonant, and the duration of this interval strongly correlates with the resulting constriction degree as predicted by the truncation analysis. [Work supported by NIH.]