A Study On Prosodic Intervention For Spastic Dysarthria Based On Vocal Fold Movement

Spastic dysarthria is caused by damage to bilateral upper motor neurons,resulting in muscle spasms related to speech motor output,which affects voice,articulation,and prosodic functions,and hinders normal social communication.Rhythm includes intonation,stress,tone,and rhythm.It does not have a separate system to form related movements,and it relies on the voice system,which is the intrinsic physiological and biological dynamic basis of rhythm.The rhythmic impairment of spastic neurological speech disorder is mainly due to vocal cord movement spasms in the voice.Spasms can cause tight adduction when the vocal cords are closed,requiring airflow to force them through the excessively adducted vocal cords,causing more unnatural pauses and reducing speech speed.Spasms can also lead to limited vocal fold flexion and movement,which can affect the pitch and pitch of the tone,leading to prosodic problems such as monotonous intonation,insufficient interrogative tone,unclear stress markers,and monotonous tone.The purpose of this study is to improve the function of various dimensions of prosodic rhythm by improving hyperkinesia of vocal cord closure and limitation of vocal cord retraction in spastic neurospeech disorder.And select a better vocal fold closure motion method and vocal fold retraction motion method to form a structured prosody strategy for application.The study of this article includes two parts,the specific content of which is:Study 1 included Experiment 1 and Experiment 2,both of which were single factor repeated measurement experiments.Experiment 1 explored four stimulation methods for vocal hyperkinesia in spastic neurogenic speech disorder: humming,anti air flow,anti water flow,and yawning and sighing.Respectively stimulate the subjects for 10 minutes to compare the prosodic voice function.The results showed that the four methods significantly reduced the vocal cord contact rate(p<0.01),and the effect of yawning and sighing was the best;The anti air flow method and anti water flow method significantly reduced the total pause time(p<0.01),increased speech speed(p<0.05),and decreased vocal effort(p<0.01),and there was no significant difference between the two methods(p>0.05);None of the four methods significantly improved prosodic stress,intonation,and tone(p>0.05).This indicates that hyperkinesia in vocal cord closure,which alleviates spasmodic neurogenic speech disorder,can positively affect prosodic and rhythmic functions.Experiment 2explored two stimulation methods for the limitation of vocal cord flexion and movement in spastic neurogenic speech disorder: singing and gliding.Respectively stimulate the subjects for 10 minutes to compare the prosodic voice function.The results showed that both singing and sliding significantly improved the pitch slope K of the entire interrogative sentence(p<0.05),the pitch slope K of the boundary tone of the interrogative sentence(p<0.01),the pitch slope K of the two tone tone(p<0.01),the pitch slope K of the four tone tone(p<0.01),and the average pitch frequency of the stress(p<0.01),and there was no significant difference between the two(p>0.05).Both singing and gliding significantly increase the range of voice,and the improvement effect of singing is better than gliding.It is shown that both singing and gliding can have a positive impact on the tone,intonation,and stress of the rhythm of spastic neural speech disorder,and singing has a better effect on broadening the limits of physiological range.Based on the results of study 1,study 2 proposed a stimulation method that combines vocal cord closure motion and vocal cord retraction motion to form a strategy that can improve the prosodic function of spastic neural speech disorder as a whole,and validated it.The results showed that after 200 minutes of intervention,among the prosodic and rhythmic parameters,the total duration of pause decreased(p<0.01)and the speech rate increased(p<0.05);In prosodic stress parameters,the average fundamental frequency of stress(p<0.01)and the peak amplitude of stress(p<0.05)increased;Among the prosodic and tonal parameters,the fundamental frequency slope K of the entire interrogative sentence increased and presented a positive value for the first time(p<0.05),while the fundamental frequency slope K of the boundary tone of the interrogative sentence increased(p<0.01);Among the prosodic tone parameters,the pitch slope K of two tones(p<0.05)and the pitch slope K of four tones(p<0.01)were significantly improved;The subjective evaluation naturalness score of prosody also significantly improved.This indicates that this strategy is comprehensive in improving the prosodic problems of spasmodic neural speech disorder,and is beneficial for improving the naturalness of listening sensation and extending it to daily communication.The innovation of this study is to use the physiological basis of prosody as a starting point to intervene in prosodic problems from the perspective of vocal fold closure hyperkinesia and vocal fold retraction limitation in spastic neurospeech disorders.A structured prosodic intervention strategy has been formed,which can achieve an overall therapeutic effect on rhythm,intonation,stress,and tone of rhythm,rather than being limited to a certain dimension.To provide some ideas and references for clinical intervention of prosodic function.