The investigators will continue the development of a computational model of phonetic structure, and employ it to help understand certain kinds of place of articulation assimilation that occur in various languages. The model is based on a particular dynamical systems approach called task dynamics, which abstractly characterizes speech gestures in terms of coordinated patterns of articulator movements during speech production. The relative timing and parameterization of the gestures comprising a given utterance are specified by a gestural score that is generated by the model's linguistic gestural component. To apply the model to assimilation, the investigators plan to collect data on the variation exhibited by the gestural structures (as defined by the model) as a function of variety of conditions, such as speaking rate and prosodic structure, from speakers of English, Russian, Arabic, and Spanish. They will model the observed patterns of variation. Because the model provides an explicit, principled connection between gestural specification and an acoustic output, it can be used to test how patterns of variation give rise to the percept of assimilation.
