Measuring Tongue Shapes and Positions with Ultrasound Imaging: A Validation Experiment Using an Articulatory Model

Abstract

Objective: The goal of this paper is to assess the validity of various metrics developed to characterize tongue shapes and positions collected through ultrasound imaging in experimental setups where the probe is not constrained relative to the subject’s head. Patients and Methods: Midsagittal contours were generated using an articulatory-acoustic model of the vocal tract. Sections of the tongue were extracted to simulate ultrasound imaging. Various transformations were applied to the tongue contours in order to simulate ultrasound probe displacements: vertical displacement, horizontal displacement, and rotation. The proposed data analysis method reshapes tongue contours into triangles and then extracts measures of angles, x and y coordinates of the highest point of the tongue, curvature degree, and curvature position. Results: Parameters related to the absolute tongue position (tongue height and front/back position) are more sensitive to horizontal and vertical displacements of the probe, whereas parameters related to tongue curvature are less sensitive to such displacements. Conclusion: Because of their robustness to probe displacements, parameters related to tongue shape (especially curvature) are particularly well suited to cases where the transducer is not constrained relative to the head (studies with clinical populations or children).

Análise ultrassonográfica quantitativa do movimento da língua em 14 fonemas do Português Brasileiro

“…Previous studies (11,27,30) have also pointed to the advantages of using ultrasonographic measures relatively to the absolute measures, precisely because the effects of inter-speaker variability are minimized. In a specific study (27) , the authors analyzed the productions of /p/, /t/, /s/ e /ʃ/ followed by vowels /a/ and /i/ in the speech of 10 teenagers using relative ultrasonographic measures, comparing two data collection conditions: with and without the use of head-stabilizer.…”

“…These studies contemplate both a qualitative and a quantitative description of patterns of speech production in adults (10,11) , in typical children (12,13) , and in different clinical groups, such as: hearing impaired individuals (14,15) , children with apraxia of speech (16,17) , glossectomized individuals (18,19) and individuals with tongue paresis (20) . Among the cited studies that aimed to analyze the typical production in adult and/or child speech (10)(11)(12)(13) , there is a limited number of individuals (varying from 6 to 10) using both qualitative and quantitative parameters to describe the tongue movement held in the production of different speech sounds (/p/; /t/; /k/; /f/; /s/; /∫/; /l/ e /r/). On the other hand, the studies that aimed to analyze speech production in different clinical groups mostly used ultrasound for therapeutic purposes, as a feedback instrument.…”

“…In the international literature, some ultrasonographic indices are described to differentiate the production of lingual phonemes of English, such as: MCI (Modified Curvature Index) (10) , Concavity, Anteriority, Asymmetry (18) , among others (11,13,20,21) . However, not all indices are sensitive to grasp the difference in typical production, not being used, until now, for clinical application.…”

Speech production after glossectomy: Methodological aspects

“…Part of the processing of the data was thus conceived in order to find a way to extract relevant information about changes in articulation across conditions, in spite of the lack of calibration. This has been largely inspired by the proposals made by Menard and colleagues in the Phonetic Laboratory of Montréal (Ménard et al, 2012).…”

Variability in Ultrasound Measurement of Hyoid Bone Displacement and Submental Muscle Size Using 2 Methods of Data Acquisition

“…Hand-held transducer placement may be more clinically useful as it is comfortable for participants [4], may reduce tissue compression when used correctly [14] and does not require sophisticated data analysis or large, and oftentimes cumbersome, equipment. This technique has been used to measure excursion of the hyoid bone [15], track laryngeal elevation [16], and quantify geniohyoid muscle movement [17] during swallowing, although measurement variability is not reported.…”