Tongue Part Movement Trajectories for /r/ Using Ultrasound

Abstract

Purpose Because it shows the movement of different parts of the tongue in real time, ultrasound biofeedback therapy is a promising technology for speech research and remediation. One limitation is the difficulty of interpreting real-time ultrasound images of tongue motion. Our image processing system, TonguePART, tracks the tongue surface and allows for the acquisition of quantitative tongue part trajectories. Method TonguePART automatically identifies the tongue contour based on ultrasound image brightness and tracks motion of the tongue root, dorsum, and blade in real time. We present tongue part trajectory data from 2 children with residual sound errors on /r/ and 2 children with typical speech, focusing on /r/ (International Phonetic Alphabet ɹ) in the phonetic context /ɑr/. We compared the tongue trajectories to magnetic resonance images of sustained vowel /ɑ/ and /r/. Results Measured trajectories show larger overall displacement and greater differentiation of tongue part movements for children with typical speech during the production of /ɑr/, compared to children with residual speech sound disorders. Conclusion TonguePART is a fast, reliable method of tracking articulatory movement of tongue parts for syllables such as /ɑr/. It is extensible to other sounds and phonetic contexts. By tracking tongue parts, clinical researchers can investigate lingual coordination. TonguePART is suitable for real-time data collection and biofeedback. Ultrasound biofeedback therapy users may make more progress using simplified biofeedback of tongue movement.

Abstracts of the 8th International Conference on Speech Motor Control Groningen, August 2022

“…Studies of American English /ô/ have found that various tongue shapes yield perceptually equivalent outcomes (Tiede et al, 2004;Westbury et al, 1998). However, tongue shapes can vary based on adjacent vowels (Mielke et al, 2010), so that rhotic syllables can also be characterized by relative movements of articulators between phonemes (Dugan et al, 2019). The extent to which these relative movements are characterized by the tongue shapes comprising their endpoints is unknown.…”