Effect of tone on consonant + vowel interaction.

Examining consonant + vowel coarticulation for American English [Agwuele et al., 16th ICPhS, 1, 617–620 (2007) and Lindblom et al., J. Acoust. Soc. Am. 121, 3802–3813 (2007)], the effect of speech tempo and emphatic stress on F2onset and F2mid of the following vowel were quantified and dissociated from the underlying traditional coupling of consonant and vowel. Thus, these two prosodic factors were shown to pose additional confound to CV coarticulation. Adopting the approach of these works, this present study examines VCV sequences in Yoruba, a tonal language, in order to determine whether lexical tone produces as additional confounding effect to the interaction between consonant and tone bearing vowel that could be shown to be separate from the traditionally expected CV bonding. The study shows that the changing pattern of tone configuration in VCV sequences, e.g., from VMCVM [M=midtone] to VLCVL [L=low tone] produces differing consonant + vowel interaction. The study provides acoustic evidence for a possible independence of the “source” from the “filter,” i.e., the resonances of the vocal tract [Fant, G. Acoustic Theory of Speech Production (1960)].