A Study On The Chinese Accent In Children With Cerebral Palsy Aged 7-9 Years Old

Dysarthria is one of the major complications of cerebral palsy(CP),which results in the dysfunctions of phonation,articulation,respiration,prosody and other subsystems in children with cerebral palsy.Stress is an important part of the Chinese prosody system.By forming different stress patterns at the Chinese lexical level and sentential level,it plays a variety of speech functions such as distinguishing meaning,constructing new information and conveying special emotions.Previous studies have found that people with dysarthria have a very unfavorable situation in the production of stress.However,there has not been a study specifically examining the production of stress in Chinese CP children.Through the lexical level(Neutral Tone)and sentential level(Focus),this study aims to investigate the prosodic adjustment ability of Chinese CP children aged 7-9 in producing stress and the interaction between it and speech perception,by means of acoustic analysis and perception experiment.This study is not only the first time to study stress in children with cerebral palsy with tonal language background,providing reference for cross-language comparison,but also promote the research on the output characteristics of speech prosody in children with cerebral palsy,in order to provide guidance for the diagnosis and speech rehabilitation of dysarthria.In word level(Neutral Tone),the prosodic feature differences in different tone and type of neutral tone with CP children and typical developing children(TD children)was compared by extracting the fundamental frequency(F0),duration et al..At the same time,the evaluation results of the two groups of children's neutral tone by normal adult listeners were analyzed to investigate its influence of on the decoding mechanism of the listeners.The main results are as follows:1.As a whole,CP group can produce neutral tone at a level close to that of TD group,their variation patterns of basal frequency and duration were similar to those of TD group.2.However,it is difficult for CP children to achieve the fine rhythm control,and their output standard is insufficient,appears in:(1)It is difficult for children with cerebral palsy to realize low-tone,for the F0 mean in some tones(T2 and T4)was significantly higher than that of TD group;(2)It is difficult for CP children to achieve a large expansion of F0 range of non-neutral tone,resulting in a lack of contrast between the neutral tone and non-neutral tone;(3)The speech rate of CP children is slower and the shortener proportion of neutral tone is smaller,which causes the time domain comparison between neutral tone and non-neutral tone too close.3.The assessment results of CP group were significantly worse than those of TD group.Listeners tended to judge the output of CP children as "non-neutral tone",and it was more difficult to identify because of the perceived conflicting prosodic information.At the sentence level(Focus),through analyzing the acoustic parameters and audience recognition rate of focus,the prosodic characteristics of focus in different tone and focus conditions between CP and TD children and the influence on the decoding mechanism of the listeners was compared.The main results are as follows:1.The CP children could not effectively use prosodic parameters such as F0 and duration to achieve the focus,appears in:(1)CP children can hardly achieve the elevation of F0;(2)CP group had too narrow focal tone domain under the two tones of T2 and T4;(3)There was no obvious downward trend of the F0 of post-focus in CP children,so there was no "PFC";(4)CP children's speech rate was slower than TD children,and there was no stable extension of focus and shortener of post-focus.2.The prosodic disorder in CP has a great negative impact on listeners' perception of their focus expression intention,for the audience recognition rate of focus in CP children is significantly lower than that of normal children.Through this study,it was found that children with cerebral palsy had prosodic control ability at the overall level,but there were still difficulties in prosodic adjustment in fine structure.