This thesis presents evidence from a formant perturbation experiment which supports the hypothesis that speech targets are multimodal. A real-time auditory feedback perturbation is used to gradually shift English speakers' formants from the vowel /E/ towards /I/. Most speakers compensate at the level of acoustics, adjusting their production towards /ae/ such that they hear themselves producing the correct vowel. Subjects' articulation is tracked with electromagnetic-articulography. The articulatory data shows that subjects tend to produce marginal /E/s at the level of articulation - remaining within the normal articulatory bounds for that vowel, while adjusting the position of individual articulators to a sufficient extent to create an acoustic compensation to the perturbation. The higher-order relationship between speed and curvature is shown to differ across different vowel phonemes. However, this measure remains constant under formant perturbation. These findings are argued to show that phonemic targets are multi-modal, having acoustical, kinematic, and dynamic components.

This thesis presents evidence from a formant perturbation experiment which supports the hypothesis that speech targets are multimodal. A real-time auditory feedback perturbation is used to gradually shift English speakers' formants from the vowel /E/ towards /I/. Most speakers compensate at the level of acoustics, adjusting their production towards /ae/ such that they hear themselves producing the correct vowel. Subjects' articulation is tracked with electromagnetic-articulography. The articulatory data shows that subjects tend to produce marginal /E/s at the level of articulation - remaining within the normal articulatory bounds for that vowel, while adjusting the position of individual articulators to a sufficient extent to create an acoustic compensation to the perturbation. The higher-order relationship between speed and curvature is shown to differ across different vowel phonemes. However, this measure remains constant under formant perturbation. These findings are argued to show that phonemic targets are multi-modal, having acoustical, kinematic, and dynamic components.