Lexical tone and segmental coarticulation.

In studying anticipatory coarticulation in emphatic CV sequences [Lindblom et al., J. Acoust. Soc. Am. 121, 3802–3813 (2007)] and in fast speech [Agwuele et al., Phonetica 68, 194–209 (2008)], it was shown that prosodically induced modulations of speech introduce additional sources of phonetic variation separate from those generated by vowel context. Both studies were successful in dissociating these additional prosodic effects from the underlying contextual vowel variation and quantifying them. The focus of this current investigation was to study CV coarticulation, using a similar set of regression metrics, but now applied to a tonal language (Yoruba). It is to be determined whether lexical tone impacts the coarticulation of consonant and vowel. Specifically, words, do tones, produce additional effects on anticipatory CV coarticulation separate from those generated by vowel-context similar to emphatic stress and increased tempo as documented by the aforementioned studies? Finally, of interest also is to examine whether different lexical tones impact C+V coarticulation differently.