A Contrastive Study Of Lexical Tone Production Between Mandarin-speaking Autistic Children And Typical-developing Children

Autism Spectrum Disorder(ASD)is a category of neurodevelopmental impairments distinguished by severe difficulty in social communication.It is frequently associated with atypical prosodic characteristics,especially in non-tonal language users.The prosodic realizations of autistic persons who speak tonal languages,however,have received little attention.To reveal the atypical mechanism of lexical tone production in children with autism,this study compared the phonetic and acoustic characteristics of Mandarinspeaking autistic and typically developing(TD)children in different tonal contexts systematically.Research questions include:(1)What are the differences in pitch,duration,and amplitude of monosyllabic words between autistic children and typicaldeveloping children?(2)What are the differences in pitch,duration,and amplitude of disyllabic words between autistic children and typical-developing children?(3)What are the differences in pitch,duration,and amplitude of neutral-toned words between autistic children and typical-developing children?Eight Mandarin-speaking autistic children aged from four to ten years old were enrolled in the experimental group.Eight kids with similar ages and genders made up the control group.This study used a picture-naming task to elicit their spontaneous speech in word level.The participants’ tonal production was recorded by the software of SpeechRecorder and processed by the software of Praat and VoiceSauce.The statistical analyses were conducted in R.Linear-mixed effect model and growth curve analysis were used to analyze linear parameters and nonlinear parameters.Based on the tonal contexts,the major findings of this study are listed as follows.For monosyllabic words’ pitch,the pitch mean of autistic children were higher than typical-developing children in T2,T3,and T4.Furthermore,autistic children exhibited flatter pitch contour and smaller pitch curvature in T3.For monosyllabic words’duration,no atypical temporal realization was found in duration between the two group.For monosyllabic words’ amplitude,autistic children’s amplitude was lower than typical-developing children in T4.In terms of disyllabic words’ pitch,higher pitch means was also found in autistic children in all tonal contexts compared to typicaldeveloping children.Flatter pitch contour was found in S2 of T3 in ASD group.In terms of disyllabic words’ duration,no atypical temporal realization was found in duration between the two group.In terms of disyllabic words’ amplitude,autistic children’s amplitude was lower than typical-developing children in T1.As for neutral-toned words’pitch,the autistic group also exhibited higher pitch mean than TD children across all tonal contexts.As for neutral-toned words’ duration,atypical temporal realization was found in autistic group.The normalized duration of T1,T4 in autistic group was longer than typical-developing children.As for neutral-toned words’ amplitude,no significant difference was found.All in all,the atypical lexical tone production of ASD children mainly focused on pitch.This study explored the differences of phonetic characteristics between autistic children and typical-developing children in tonal language when they produced various tones spontaneously.According to the phonetic study,the ASD group had considerably atypical characteristics and rigid pitch curves in monosyllabic words,disyllabic words,and neutral-toned words.Clinically,these results could be explained by underlying neural variations and the ability of motor-control in autistic kids.The overview of autistic children’s tone production is helpful to the language rehabilitation of Chinese autistic children,which can also provide some reference for the evaluation of tone training effect of autistic children.