Prosodic strengthening at the edges of prosodic domains in sighted and blind speakers

Abstract

Recent studies have shown that when producing isolated vowels, congenitally blind speakers produce smaller displacements of the lips (visible articulators), compared with their sighted peers. To investigate the role of visual experience on articulatory gestures used to produce salient speech contrasts, the production of vowels at the edges of low-level prosodic domains and high-level prosodic domains (in which gestures are reported to be strengthened) was studied in adult speakers of Quebec French. Ten sighted and ten congenitally blind participants were recorded during the production of the vowels /i/, /y/, /u/, /a/ in initial and final positions of two prosodic domains: word and intonational phrase. Synchronous acoustic and articulatory data were recorded using the Carstens AG500 Electromagnetic Articulograph system. Formant measures as well as displacements of the lips and tongue were analyzed. The results revealed that speakers produced larger ranges of lip and tongue movements at the edges of higher prosodic domains than at the edges of lower ones. Formant spaces and durational data are presented. The use of visible (lip and jaw) and invisible (tongue) articulators to implement the prosodic structure is discussed