The Application Of Exaggerated Articulation-accent Method On Mandarin Vowel Production Of Dysarthria

Patients with dysarthria have abnormal vowel production due to nervous system damage,which affects speech intelligibility and reduces the efficiency of communication.Accent Method and exaggerated articulation can improve articulation and prosody,and are used to improve vowel production,articulation clarity and speech intelligibility.However,the intervention effect of these two methods and their combination on mandarin vowel production has not been systematically verified.The purpose of this study is to investigate the effect of accentuation combined with exaggerated articulation on the motor articulation and prosodic function of vowels in patients with dysarthria,and to formulate the treatment strategy for vowels in patients with dysarthria,and then to verify its clinical application effect through case studies.It is expected to improve the vowel production of patients from articulation movement and prosody function,and improve the quality of speech communication.This study includes three parts:1.The first study included experiment 1 and experiment 2,both of which were two-group experimental design.The differences of patients with dysarthria and normal adults were compared from the two aspects of monophthong vowels and compound vowels.The results showed that there were differences in articulation,formant parameters and prosodic parameters between the patients and the normal subjects.The accuracy of target vowels（P<0.01）and words（P<0.001）were lower in monophthong vowels of patients;The formant parameters such as F1 a,F2i,mandibular distance,lingual distance,F2i/F2 u and VAI（P < 0.001）decreased,while F2u（P < 0.01）increased;Mean F0,articulation rate（P<0.05）,F0 standard deviation,F0 range,intensity standard deviation,intensity range（P<0.001）were smaller in prosodic parameters.The accuracy of target vowels（P < 0.05）and words（P<0.001）in compound vowels were also lower of patients;For formant parameters,the F2 slopes of /ai/,/ua/（P<0.05）,/uai/（P<0.001）and the F2 extent of /uai/（P<0.01）decreased.The results showed that the movement range of articulation organs was reduced,the difference between vowels was reduced,the transition speed of articulation organs was slowed down,the pitch,loudness and speed of rhythm were impaired,the articulation clarity was decreased,and the speech intelligibility was affected.2.Study 2 included Experiment 3 and Experiment 4,both of which were singlefactor repeated measures experimental design.The effects of accentuation combined with exaggerated articulation were compared from monophthong vowels and compound vowels production.The results showed that articulation rate of accentuation decreased（P<0.05）,and clarity was improved in words containing single vowels（P<0.01）.The effect of accentuation with exaggerated articulation on improving vowel production was more obvious,which showed that the correct rate of words（P<0.01）was increased;In monophthong vowels,F1 a,VSA,VAI,mean F0,intensity range（P<0.01）and mandibular distance（P<0.05）were increased,while the articulation rate（P<0.001）was decreased.Mean F0,intensity standard deviation and intensity range（P<0.05）increased,while articulation rate（P<0.001）decreased in compound vowels.The results show that accentuation with exaggerated articulation can improve the articulation motor and prosodic function and improve speech intelligibility.Patients with dysarthria can use this way to improve vowels production and improve the quality of speech communication.3.In the third study,based on the results of the first and second studies,the intervention strategy of Accent Method and exaggerated articulation applied to the vowel production of patients with dysarthria was proposed and verified.The results showed that after 10 times of training,the accuracy of vowels（90.91%）and speech intelligibility（94.4%）of the patients were improved;In monophthong vowels,F1 a,mandibular distance（P<0.05）,tongue distance,mean F0,F0 standard deviation,F0range（P<0.01）,F2i/F2 u,VSA（P<0.001）were improved.F2u（P<0.001）and articulation rate（P<0.01）decreased.F2 slope of /ua/,articulation rate（P<0.001）,F2 slope of /uai/（P<0.01）of compound vowels decreased.F2 extent of /uai/（P<0.001）,mean F0,intensity standard deviation（P<0.01）,F0 standard deviation,F0 range,and intensity range（P<0.05）all increased.The results showed that after Accent Method with exaggerated articulation treatment,the movement range of articulation organs increased,the transition speed of articulation organs slowed down,the pitch level and change range,the loudness change range increased,the vowel production improved,and the speech intelligibility improved.The innovation of this study is to explore the improvement effect of Accent Method with exaggerated articulation on the vowel production of patients with dysarthria in mandarin,formulate and verify the therapy strategy,provide reference for clinical intervention of vowel production of patients with dysarthria,and have some practical value and theoretical significance.