An Experimental Analysis Of Pronunciation Defects In Common Speech Stream After Children's Cleft Palate Surgery

In this paper,we use the method of subjective listening and objective analysis to investigate the pronunciation of basic vowels,compound vowels,voiceless consonants,voiced consonants and nasal finals in the continuous conversation of children with the velopharyngeal closure complete group(VPC)and velopharyngeal closure incomplete group(VPI)after cleft palate surgery.Compared with the performance of normal children,we conclude the pronunciation defects of children with cleft palate and make some suggestions for speech therapy.The main conclusions of this paper are as follows1.The performance of the basic vowels of the children in the VPC group and the VPI group is:the accuracy rate of the vowels of the disyllabic words in the two groups of children on the sense of hearing,the VPC group is i(90%)>(?)(79%)>y(70%)>(?)(65%),the VPI group is a(94%)>i(84%)>u(81%)>(?)(80%)>y(64%)>(?)(51%)>(?)(27%)Regardless of whether it is a disyllabic word or a sentence,the triangle area of the vowel triangles in the VPC and VPI groups is smaller than that in the normal group,the boundaries of each vowel are not clear,the crossover phenomenon is serious,and the tongue position is different from the normal group.In terms of nasalization,the nasalization of each vowel is expressed as follows:the VPC group in the disyllabic words is i(43)>y(39)>(?)(34)>(?)(33)>u(32)>(?)(25)>a(24),the VPI group in the disyllabic words is i(79)>y(74)>u(69)>(?)(64)(?)(62)>(?)(45)>a(40)The VPC group in the sentences is i(42)(?)(41)>(?)/u(32)>(?)(22)>a(21),and the VPI group in the sentences is i(79)>(?)(77)(?)(73)>u(65)>(?)(47)>a(40).Combining hearing acoustics and nasalization,the main types of vowel pronunciation errors are:nasalization;complex vowelization;substitution;backward movement of the pronunciation part;ambiguity2.The performance of the compound vowels in the VPC and VPI groups is:the performance of the compound vowels in the sentences of the two groups in the sense of hearing.The pronunciation of the/au/,/ou/,/uo/,/i?/,/y?/is worse in the VPC group,and the pronunciation of the/ei/,/au/,/ou/,/uo/,/i?/,/y?/is worse in the VPI group,and the rest is better.The acoustic performance of the VPC group and the VPI group was different from that of the normal group on the tongue position·The degree of nasalization showed that the compound vowels in the VPC group did not have excessively high nasal sounds,and the compound vowels in the VPI group had generally high nasal sounds.Combining hearing acoustics and nasalization,the types of compound vowel pronunciation errors are mainly:substitution;monophthongization;addition of nasal final/(?)/;ambiguity.3.The performance of children's voiceless consonants in the VPC group and the VPI group is:the performance of the voiceless consonants of the disyllabic words in the two groups of children.The VPC group is x(92%)>c(89%)>f(81%)>t(79%)=k(79%)>ph(78%)=tc(78%)>p(77%)>th(76%)>tch(73%)>s(72%)>kh(71%)>s(70%)>tsh(67%)>ts(64%)>ts(62%)>tsh(48%).The VPI group is:x(78%)>f(70%)>s(60%)>c(58%)>ph(56%)>th(53%)>kh(39%)>p(30%)>T(29%)>tch(26%)>k(24%)>s(23%)>tsh(18%)>tc(16%)>tsh(10%)>ts(9%)>ts(8%).In terms of pronunciation methods,the affricative is the worst From the point of pronunciation,the apical is the worst.The acoustic performance is that the onset of voiceless consonants in disyllabic words or sentences in the VPC and VPI groups is shorter than in the normal group.The experiment found that the VPC group/p/,/th/,/kh/,/t/,/k/,/c/,/s/,/s/,/f/,/x/,/tc/,/tch/,/tsh/,/tch/is significantly different from the normal group;VPI group/p/,/ph/,/th/,/k/,/x/,/tch/,/ts/,/tc/is significantly different from the normal group.Combining hearing sense and acoustics,the types of pronunciation errors of voiceless consonants are:missing,replacement,nasal aspiration,and ambiguity4.The performance of children's voiced consonants in the VPC group and the VPI group is:the performance of the disyllabic words in the two groups of children on the sense of hearing.The VPC group is(?)(85)>m(82)>n(81)>1(70),The VPI group is m(77)>1(43)>n(31)>(?)(28).The acoustic performance is that the duration of the initial consonants in the VPI group and the VPC group is slightly shorter than the normal group,but the difference is not significant.In terms of nasalization,the degree of nasalization of each voiced consonants is shown as follows:the VPC group in the disyllabic words is m(88)=n(88)>1(41)=(?)(41),and the VPI group in the disyllabic words is n(90)>m(87)>1(68)>(?)(51).VPC group in the sentences is m(85)>n(82)>1(30),and VPI group in the sentences is m(84)>n(83)>1(56).Non-nasal initials may have excessive nasal sounds.Combining auditory acoustics and nasalization,the types of pronunciation errors of voiced consonants are:missing,4 consonant initials replacing each other,/(?)/substituting5.The nasal finals of the children in the VPC group and the VPI group are:the performance of the disyllabic words in the two groups of children on the sense of hearing,the VPC group is-n(89%)>-(?)(75%),and the VPI group is-n(75%)>-(?)(62%),the performance of the posterior nasal final of VPI group was slightly worse.The acoustic performance is that there are differences between the nasal final formants of the VPC group,the VPI group and the normal group.In terms of nasalization,the degree of nasal finals and nasalization are shown as follows:the VPC group in the disyllabic words is-(?)(80)>-n(76),and the VPI group in the disyllabic words is-(?)(89)>-n(84).The VPC group in the sentence is-n(89)>-(?)(83),and the VPI group in the sentence is-(?)(89)>n(86).Anterior nasal final/-n/weakened nasalization is more common and less stable,and posterior nasal final/-(?)/is relatively stable Combining hearing acoustics and nasalization,the types of pronunciation errors of nasal finals are:missing;/-n/and/-?/are replaced with each other.In summary,due to the different physiological structure of the children in the VPC group and the VPI group,the differences in hearing discrimination,acoustics,and nasalization are all obvious.Both groups of children showed abnormal resonance,but the children with VPI group had more severe nasal sounds than those with VPC group,so the nasalization degree of basic vowels and compound vowels were higher in VPI group than in VPC group.The consonants of the two groups of children will appear ambiguous,but the children in the VPI group have abnormal articulation due to excessive nasal airflow.Cleft palate children's pronunciation is not clear,which seriously affects communication,so it is particularly important to provide rehabilitation strategies for vowels and consonants in the continuous conversation.Here,I only offer some suggestions for cleft palate speech therapy.For children with insufficiency of the pharyngopharyngeal closure group,the most important thing is to perform a second operation,and then perform speech training after the opharyngeal closure is complete.Speech training is particularly important for children with a complete pharyngeal closure group.1.Basic vowel training sequence practice/a/,/?/,/u/,then/i/,/y/,and finally/?//?/.After you have practiced the basic vowels,learn compound vowels again.Pay attention to/au/,/ou/,/ei/,/uo/,/i?/,/y?/.2.Consonant practice sequence:From the perspective of pronunciation method,practice fricative first,then stop,and finally affricative.From the perspective of aspirating,practice the aspirating sound first,then practice the aspirating sound.From the point of pronunciation,practice the bilabial first,then the lingual,and finally the apical.The specific practice depends on individual circumstances.It is easy to make difficult to match auxiliary elements in practice.You can practice vowels and consonants in the order of single-voice?double-voice? sentence.