Thesis defence : Geneviève MELONI

This thesis work investigates Speech Sound Disorders (SSD). SSD are defined as a delay in speech sound development affecting acceptability and intelligibility of speech. SSD are the most common communication disorder in the pediatric population. Children with SSD are at high risk for later academic and social inclusion. Despite the high prevalence and possible long-term consequences, there are currently few assessment tools available to diagnose French-speaking children with SSD and characterize the disorder. The theoretical part of this work highlights the lack of diagnostic tools.This work intends to create a speech sound assessment tool, based on a psycholinguistic model to diagnose children with SSD. The assessment tool, named EULALIES, includes five tasks, each involving different levels of the psycholinguistic model: (1) a lexicality judgment task, (2) a picture-naming task, (3) a nonword repetition task, (4) a diadochokinetic task, and (5) a syllable repetition task. Data were collected from 119 typical children and 9 children with SSD.The first part of the results focuses specifically on the nonword repetition task and describes the validity of this task. Our results highlight the fact that nonword repetition performance depends on children's age, phonological short-term memory skills, inclusion of a real word in the nonword, syllable structure, and length of the pseudoword. Data collected show that the task is not sensitive to sociolinguistic factors such as socioeconomic status or linguistic status, which is what we were looking for from a clinical perspective.The second part of the results addresses the differential diagnosis between childhood apraxia of speech and phonological disorder, both of which being subtypes of SSD. The assessment tool reveals specific markers for childhood apraxia of speech, such low diadochokinetic rate or errors on vowels. Contrary to what is described for English, some markers seem to be less relevant for French-speaking children. This is the case for schwa epenthesis.At the end of this work, we argue that children with SSD assessment should be based on the analysis of error patterns produced by the child as well as on a psycholinguistic approach. This helps to better describe the child's speech profile and to offer an adapted intervention.

Encadrants :
- Directeur de thèse : Hélène LOEVENBRUCK - helene.loevenbruckuniv-grenoble-alpes.fr (helene[dot]loevenbruck[at]univ-grenoble-alpes[dot]fr)
- Codirecteur : Andrea MACLEOD -  andrea.macleodrea.ulaval.ca (andrea[dot]macleod[at]rea[dot]ulaval[dot]ca) -
- Codirecteur : Douglas SHILLER  douglas.shillerumontreal.ca (douglas[dot]shiller[at]umontreal[dot]ca) -
- Co-encadrant : Anne VILAIN  anne.vilaingipsa-lab.grenoble-inp.fr (anne[dot]vilain[at]gipsa-lab[dot]grenoble-inp.)

Keywords of the thesis: evaluation, psycholinguistic model, Speech Sound Development Disorder, children, differential diagnosis, Francophonie,

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