Tongue Body Loops in Vowel Sequences

Abstract. The tongue often shows some forward movement during the closure phase of velar consonants, resulting in elliptical trajectories (loops) in symmetrical VCV utterances. Several hypotheses exist for the cause of these loops, but none can consistently explain all observations. This study demonstrates that loops also occur in V1-V2-V1 sequences with no consonants involved. It is shown that both the direction of the loops and the relative loop widths vary systematically with the orientation of the main movement line between the vowels V1 and V2. From these observations we argue that different biomechanical properties of the tongue muscles are the main cause for loops. Model simulations support this conclusion.