Cross-Linguistic Bracing: A Lingual Ultrasound Study of Six Languages

Abstract

Lateral bracing refers to contact of the sides of the tongue along the upper molars or palate; evidence from articulatory analysis of native English speakers as well as 3D biomechanical simulations suggests that bracing involves mechanical support which occurs consistently throughout speech [Gick et al. 2017. J Speech Lang Hear Res. 60(3):494-506]. Release of lateral bracing occurs only during some lateral consonants and low vowels. The current study tests for the presence of active lateral bracing in seven languages: Cantonese, English, Korean, Mandarin, Portuguese, Spanish, and Turkish. Ten native speakers of these languages (2 each for English, Mandarin and Korean and one each for the other languages) read aloud passages of the North Wind and the Sun [Handbook of the IPA, 1999] while a coronal ultrasound video of their tongue was recorded. Tracings were made from still images of the M-mode ultrasound videos, and measurements of the vertical motion of the tongue midline and both edges were taken. The percentage of time the tongue is not laterally braced was calculated. Active lateral bracing is implicated if the left and right edges of the tongue are less variable in vertical motion than midline and/or positioned at a stable baseline height for a larger percentage of time than they are lowered. Preliminary analysis supports the hypothesis that tongue bracing in speech exists regardless of language.