Optimal control of speech with context-dependent articulatory targets

This paper presents a computational implementation of phonetic planning which consists of choosing the position of articulatory targets which satisfy conflicting linguistic and extra-linguistic requirements. We present a minimal model that considers intelligibility and least effort as task requirements. To achieve the context-dependent variability of targets, our model approximates intelligibility as a function of target phoneme recognition probability given a vector of articulatory parameters. Preliminary experiments show that our minimal computational model of phonetic planning is able to predict two types of hypoarticulation by adjusting the weight assigned to effort: vowel centralization and stop consonant lenition.