Articulatory parameterization in Trique tone production: Distinguishing co-production from coarticulation

The production of a tone in a tonal language is typically influenced by adjacent tonal targets. Within the literature, all such influences on F0 are considered part of tonal coarticulation. Yet, conflating all these effects under "coarticulation" results in an assortment of different processes within a tone language which lack a common motivating principle. In this talk, we present tone production data from Itunyoso Trique (Oto-Manguean). The data consists of 5 repetitions of 24 sentences spoken at two speech rates (fast/normal) by 8 native speakers. The medial target word was one of four tones (/45/,/4/,/32/,/2/), while the adjacent words were one of six tones (/45/,/43/,/32/,/3/,/2/,/1/). F0 data was extracted and time-normalized. Two patterns were observed. First, adjacent tones influenced F0 at the onset and offset of target tones. Second, global changes in F0 contour occurred for certain tones. All such effects were stronger during fast speech rate. We argue that these effects, often grouped together as coarticulation, have distinct explanations within an Articulatory Phonology framework. Transitional alignment differences at tonal onsets and offsets are modelled by including a default tone attractor in transitions, whereas global changes in F0 contour are modelled by modulating gestural target parameters.