Differences between the production of [s] and [ʃ] in the speech of adults, typically developing children, and children with speech sound disorders: An ultrasound study

Abstract

This study describes the criteria that are used in ultrasound to measure the differences between the tongue contours that produce [s] and [ʃ] sounds in the speech of adults, typically developing children (TDC), and children with speech sound disorder (SSD) with the phonological process of palatal fronting. Overlapping images of the tongue contours that resulted from 35 subjects producing the [s] and [ʃ] sounds were analysed to select 11 spokes on the radial grid that were spread over the tongue contour. The difference was calculated between the mean contour of the [s] and [ʃ] sounds for each spoke. A cluster analysis produced groups with some consistency in the pattern of articulation across subjects and differentiated adults and TDC to some extent and children with SSD with a high level of success. Children with SSD were less likely to show differentiation of the tongue contours between the articulation of [s] and [ʃ].

Ultrasonographic analysis of lateral liquids and coronal fricatives: judgment of experienced and non-experienced judges

“…After the inspection of the images and inspiring on the existing description in the literature 5,17 , the categories for the assessment of the TUS images described in figure 2 were defined.…”

“…For Brazilian Portuguese (hereinafter BP), in particular, there is already a qualitative TUS description for the typical production in adults of the coronal liquids 5 and the coronal fricatives 17 . These sounds were privileged by the authors because they presented late acquisition and were commonly involved in substitution processes in atypical speech.…”

“…The ultrasound contour of the tongue of /∫/ was characterized by the raised tongue with presence of curvature of the dorsum to generate palatal turbulence; while for /s/ four distinct patterns were described: 1) absence of sharp curvature of the dorsum or root of tongue; 2) presence of sharp curvature of root and dorsum in descending direction; 3) presence of a sharp curvature of root and dorsum in an upward direction, and 4) the presence of sharp curvature and more anterior dorsum 17 .…”

Evidence for Speech Sound Disorder (SSD) Assessment

“…Both EGG and aerodynamic measures show quite interesting outcomes for children with SSD who present the phonological process of devoicing of fricatives and plosives, which is very common in Brazilian-Portuguese (BP) [42,43]. Ultrasound tongue imaging (UTI) is a tool used in articulatory analysis because it allows real time visualization of tongue movement, allowing speech-language therapists to visualize how the lingual sounds are produced, mainly in cases of substitutions of anterior sounds by posterior sounds (or vice versa) [44][45][46][47][48], as well as in cases of distortions [49,50].…”

“…A recent study [46] described ultra sonographic measures for tongue contours during the production of the sounds /s/ and /∫/ in adults, typically developing children (TD), and children with SSD with the palatal fronting phonological process. Overlapping images of the tongue contours that resulted from the production of the /s/ and /∫/ sounds of 35 individuals were analyzed to select 11 spokes on the radial grid that were spread over the tongue contour ( Figure 5).…”