A Study On The Effect Of Real-time Visual Feedback On Imitative Vocalizations Of Late Talkers

Language delay is one of the common types of language disorders in children,an d a considerable number of them are characterized by expressive delay,which is calle d late talkers（LTs）.The obvious feature of late talkers is that their early vocabular size is extremely limited,even staying in the stage of the prelinguistic vocalization for a long time.The early vocalization of late talker children is characterized by slow dev elopment,lack of consonants and few canonical babbles,resulting in low mean babbli ng level（MBL）and low syllable structure level（SSL）.Previous studies found that the mature development of early vocalization can lay the foundation for pronunciation an d promote the meaning construction of speech and the functional language,while verb al imitation is not only the initial form of speech or language development,but also th e strategy for children to establish spoken language.Therefore,this study is based on verbal imitation to improve the early vocalizations level of late talker children.In this study,experiments were conducted to explore the effects of two kinds of r eal-time visual feedback（real-time animation trajectory feedback and real-time mirror feedback）on each dimension of imitative vocalization of late-talking children.Accor ding to the experimental results and combined with the results of previous research,a comprehensive,multi-element intervention strategy based on real-time visual feedbac k was developed,and the intervention strategy was verified by clinical experiments.T he specific research contents and results are as follows:1.Study Ⅰ compared the effects of two kinds of real-time visual feedback on ea ch dimension of imitative vocalization in 15 late talker children.The research results s how that compared with the pre-test,the frequency indicators,accuracy indicators,an d duration imitation indicators under the real-time animation track feedback have bee n significantly improved.The average number of imitation indicators has increased fr om 0.87 to 1.85.There is a very significant difference（p<0.001）;various indicators of frequency and accuracy under real-time mirror feedback have been significantly impr oved,and the mean number of correct pronunciations of whole words has increased fr om 3.67 to 9.53,with a very significant difference（p< 0.001）.The comparison of the t wo experiment conditions shows that the real-time mirror feedback is significantly bet ter than the real-time animation trajectory feedback in terms of the average imitation a ccuracy and the number of correct imitations of the whole word（p=0.001,p=0.01）,an d real-time mirror significantly improved duration imitation（p=0.001）.2.Study Ⅱ stood on the above experimental results and related research results,and then formulated an intervention strategy for imitative vocalization,which is based on real-time visual feedback,and verified through a single-group pre-and post-test e xperiment.A total of 10 children with delayed speech were intervened 12 times.The r esults showed that the various indicators of imitative vocalization of late-talking child ren after intervention included the average number of imitations,the number of redupl icated syllables imitations,the number of two-syllable imitations,the average imitatio n accuracy,the number of correct imitations of whole words,the duration of imitation,and the true imitation.The number of words has been significantly improved.Among them,the mean of the average number of imitations increased from 0.54 to 1.99,and the number of monosyllabic imitations increased from 3.40 to 8.00.The improvement of the two indicators was the most significant（p<0.01）.The innovation of this study lies in:（1）exploring the effects of two kinds of realtime visual feedback stimuli on imitative vocalization of late talkers;（2）formulating a set of comprehensive and multi-element interactive intervention strategies based on r eal-time visual feedback;（3）language advanced training model of "imitative vocaliza tios to functional ture words",which provides a new train of thought for speech langu age rehabilitation.The intervention strategy for imitative vocalization that is based on real-time visual feedback can synchronously feedback the voice and oral movements of late talking children when imitating vocalization,improve the level of imitation,an d promote the vocalizations of prelinguistic stage from imitation to functional ture w ords,so as to improve the functional language level of late talkers.