The phonetic context of American English flapping: quantitative evidence.

The phonetic context in which word-medial flaps occur (in contrast to [th]) in American English is explored. The analysis focuses on stress placement, following phone, and syllabification. In Experiment 1, subjects provided their preference for [th] or [[symbol: see text]] in bisyllabic nonce words. Consistent with previous studies, flaps were preferred before stressless syllables and [th] before stressed syllables, but the following phone also exerted a small degree of influence. Experiments 2 and 3 tested whether [th] or [[symbol: see text]] are associated with a particular syllable position in bisyllabic words. They demonstrate that [th] is favored in onsets, while [[symbol: see text]] is not consistently placed in either the onset or coda, nor is it generally ambisyllabic. These findings contradict analyses that posit syllable division as a conditioning factor in the appearance of [th] versus [[symbol: see text]]. Experiment 4 examined the pronunciation of 480 multisyllabic words from the TIMIT corpus. VCV was seen to favor [[symbol: see text]], while VCV favored [th]. In addition, flaps tend to be followed by syllabic sonorants and [th] by tense vowels. Because the following phones that influenced [th] and [[symbol: see text]] in Experiment 4 differ from those that were significant in Experiment 1, more research is necessary into the effect that following phones have on the appearance of [th] and [[symbol: see text]].