Emergent consonantal quantity contrast and context-dependence of gestural phasing

Embodied task dynamics is a modeling platform combining task dynamical implementation of articulatory phonology with an optimization approach based on adjustable trade-offs between production efficiency and perception efficacy. Within this platform we model a consonantal quantity contrast in bilabial stops as emerging from local adjustment of demands on relative prominence of the consonantal gesture conceptualized in terms of closure duration. The contrast is manifested in the form of two distinct, stable inter-gestural coordination patterns characterized by quantitative differences in relative phasing between the consonant and the coproduced vocalic gesture. Furthermore, the model generates a set of qualitative predictions regarding dependence of kinematic characteristics and inter-gestural coordination on consonant quantity and gestural context. To evaluate these predictions, we collected articulatory data for Finnish speakers uttering singletons and geminates in the same context as explored by the model. Statistical analysis of the data shows strong agreement with model predictions. This result provides support for the hypothesis that speech articulation is guided by efficiency principles that underlie many other types of embodied skilled action.