Articulatory setting as global coarticulation: Simulation, acoustics, and perception

Abstract

Articulatory settings, language-specific default postures of the speech articulators, have been difficult to distinguish from segmental speech content [see Gick et al. 2004, Phonetica 61, 220-233]. The simplest construal of articulatory setting is as a constantly maintained set of tonic muscle activations that coarticulates globally with all segmental content. In his early Overlapping Innervation Wave theory, Joos [1948, Language Monogr. 23] postulated that all coarticulation can be understood as simple overlap, or superposition [Bizzi et al. 1991, Science 253, 287-291], of muscle activation patterns. The present paper describes an implementation of Joos’ proposals within a modular neuromuscular framework [see Gick & Stavness 2013, Front. Psych. 4, 977]. Results of a simulation and perception study will be reported in which muscle activations corresponding to English-like and French-like articulatory settings are simulated and superposed on activations for language-neutral vowels using the ArtiSynth biomechanical modeling toolset (www.artisynth.org). Simulated visible and acoustic outputs presented to perceivers familiar with both languages speak to the question of whether overlapping muscle activations generate outputs that look and sound language-appropriate to perceivers, testing a unified, context-independent model for both coarticulation and articulatory setting. [Research funded by NIH Grant DC-02717 and NSERC.]