Lucie Van Bogaert promoveerde op 5 maart 2024 over 'Het ondersteunen van de spraakontwikkeling
bij CI-kinderen: de meerwaarde van auditieve verbale therapie en cued speech bij Franstalige kinderen.
Op 5 maart 2024 doctoreerde Lucie Van Bogaert aan de Universiteit van Grenoble met haar proefschrift "Sustaining Speech Development in Deaf Children with Cochlear Implant: The Contribution of Auditory Verbal Therapy and French Cued Speech".
Lucie Van Bogaert is één van de 15 studenten die een doctoraal proefschrift schreven binnen het COMM4CHILD project.
Hieronder vind je de Engelstalige samenvatting van haar proefschrift:
Title : Sustaining Speech Development in Deaf Children with Cochlear Implant: The Contribution of Auditory Verbal Therapy and French Cued Speech
Key words: deaf children, cochlear implants, Auditory Verbal Therapy, French Cued Speech, speech production, speech perception, working memory.
Abstract: Hearing loss can impact the cognitive and linguistic development of a child. Cochlear implants are designed to improve speech sound perception, but the auditory information provided by the cochlear implant remains limited, which can lead to spoken language difficulties. Therefore, for parents of deaf children who choose to use spoken language with their child, it is important to implement communication aids. This thesis aims to quantify the use of these tools and methods in France and their potential benefits for speech development.
The first study of this thesis is a survey documenting the tools and methods used by parents and professionals in France, based on online surveys. It provides better description of current speech therapy and parental practices with deaf children. This study led us to focus on two approaches based on contrasting theoretical principles: Auditory Verbal Therapy (AVT), which is based on enhanced use of the auditory modality, and Cued Speech (CS), a manual code designed to be used in addition to lip-reading, the principle of which is therefore the co-use of the auditory and visual modalities.
The second part of this thesis aims to evaluate the benefits of these two approaches on speech perception, speech production and working memory. It comprises four experimental studies using five different tasks targeting different linguistic processes: a phonological alterations detection task, a picture naming task, a non-word repetition task, a verbal working memory task (forward verbal span), and a visuo-spatial working memory task (forward visuo-spatial span). Children aged 5 to 11 were divided into four groups: typically hearing children, deaf children with CI who were enrolled in an AVT approach (AVT group), deaf children with CI with a high level of CS proficiency (CS+ group), and deaf children with CI with a low level of CS proficiency (CS- group). The scores of the deaf children were compared with the typical variability of hearing children of the same age.
The results show that CS- children have lower performance than normal-hearing children on detection of phonological alterations and picture naming tasks. AVT and CS+ children achieve similar speech perception and production performance to normal-hearing children. For the pseudoword repetition task, which involves processing new phonological structures, all the deaf children had lower performance than peers with typical hearing. Finally, all deaf children show working memory performance (verbal and visuo-spatial) within the expected norms for their age.
In conclusion, the findings of these studies suggest that a high level of CS proficiency, or participation to an AVT approach, can contribute to the development of phonological skills in speech production and perception in children with CI. Additionally, the results of these studies confirm the fact that cochlear implantation alone is not sufficient for a deaf child to develop adequate speech perception and production skills. This work has clinical, educational, and societal implications, emphasizing the need to raise awareness among those involved in the care of deaf children (such as parents, speech therapists, teachers, and doctors) about the limitations of speech perception by cochlear implants and the need to consider specific speech rehabilitation strategies, particularly during the early years. It also questions the complexity of evaluating an approach to sustain phonological development and highlights the diversity of factors that need to be considered when supporting parents in their linguistic choices.