V-to-V coarticulation may be extinct in the wild

Abstract

Ever since the results of [S. E. G. Öhman, “Coarticulation…,” J. Ascoust. Soc. Am. 39, 151 (1966)] that a vowel could affect the preceding one, the phenomenon of anticipatory VCV coarticulation has been a subject of study. Most results establishing these effects have been obtained from curated laboratory speech [e.g., M. Grosvald, “Interspeaker variation…,” J. Phonetics 37, 173 (2009)], showing anticipatory V-to-V coarticulation across one, two and three syllables in English utterances. Here, we attempted to replicate these findings “in the wild” using the Buckeye Corpus of conversational English. F1 and F2 of [ʌ] or [ə] tokens were obtained in all [ʌ/ə]C(C…)V contexts. Two-dimensional Kolmogorov-Smirnoff tests were carried out to compare the F1/F2 distributions of these tokens in different contexts. The formant distributions of [ʌ/ə] in specific vowel contexts were also compared with the total formant distributions of [ʌ/ə] in all contexts. The replication effort was a failure. Essentially no significant differences of the [ʌ/ə] formant distributions could be found among the data, no matter how extreme the difference of the following vowel (e.g., [i] vs [ɑ] contexts). This poses a problem for theories of speech perception which rely on such effects.