Interspeaker variation in the extent and perception of long-distance vowel-to-vowel coarticulation

The phenomenon of coarticulation is relevant for issues as varied as lexical processing and language change, but research to date has not determined with certainty how far such effects can extend. This study investigated the production and perception of anticipatory vowel-to-vowel (VV) coarticulation. First, 20 native speakers of English were recorded saying sentences containing multiple consecutive schwas followed by [i] or [а]. The resulting acoustic data showed significant VV coarticulatory influence up to three vowels before the context vowel, a greater distance than has been seen in previous studies. However, there was substantial variability among speakers in this regard. The perceptibility of these effects was then tested using behavioral methodology; even long-distance effects were perceptible to some listeners. Subjects’ coarticulatory production strength and perceptual sensitivity were positively, but only weakly, correlated. Although the very slowest speakers tended to coarticulate less than the rest, speech rate and coarticulatory strength were not significantly correlated for the group as a whole.