Auditory feedback control of inter-articulator speech coordination: Evidence from tongue and jaw movements

Abstract

In order to test whether and how immediate auditory feedback is involved in the coordinated action of sets of speech articulators, the current research quantified changes in the temporal and spatiotemporal relations between jaw and tongue tip movements in response to noise masking. Normal-hearing talkers recorded /tV#Cat/ utterances using electromagnetic articulography, with alternative V (/ɑ/-/ɛ) and C (/t/-/d/), across variation in production rate (fast-slow) and stress (first syllable stressed-unstressed). Approximately 240 utterances were produced in two conditions: normal listening and auditory feedback masking. Two kinematic measures were obtained: (1) timing of tongue-tip raising onset for medial C, relative to jaw opening-closing; and (2) angle of tongue-tip raising onset, relative to the jaw phase plane. In the normal listening condition, any manipulation that shortened the jaw opening-closing cycle reduced both the relative timing and phase angle of tongue-tip movement onset. In the masking condition, specific changes were observed in how consistently the phase angle of tongue-tip movement onset scaled with jaw opening–closing across rate and stress variation, but not in the relative timing of tongue-tip movement onset. Collectively, these findings suggest that the spatiotemporal phasing between articulator movements relies more on immediate auditory feedback than the relative timing between ongoing articulator movements.