Yu et al.

Int Chin J Dent 2003; 3: 105-110.

The study on the acoustic features of congenital velopharyngeal
insufficiency
Liying Yu, DDS,a Guomin Wang, DDS,b Yang Chen, DDS,b and Yilai Wu, DDSbaShanghai Huashan Hospital, Fudan University, and bNinth People’s Hospital,
Shanghai Second Medical University, Shanghai, P. R. China

Purpose: To study the acoustic features of the patients with congenital velopharyngeal insufficiency(CVPI).
Materials and Methods: The acoustic features of 28 patients with CVPI were analyzed with the computerspeech lab, and compared with the features of 20 controls.
Results: It was not the same on each syllable; from phonetic images, F1, F2 and F3 of the controls wereclearer than those of the patients, the other districts of the controls were lighter than those of the patients.
F1 of the patients was darker and broader, their F2 and F3 were lower, weaker and broader. Among F1, F2and F3 of the patients, there were some extra formants. Erected stripes and fills before the vowel of thepatients were fewer than those of the controls.
Conclusion: There were apparent distinctions in F2, B2, F3 and B3 between the patients and the controls,
and there was significant difference in phonetic images between the two groups, especially in Formants,and consonants. (Int Chin J Dent 2003; 3: 105-110.)
Clinical Significance: The results of the current study demonstrate that the patients with CVPI have thesignificant differences with the normal in speech, which will help to determine the status of the patient
before and after surgery.
Key Words: acoustic features, congenital velopharyngeal insufficiency, misarticulation.

Introduction
Congenital velopharyngeal insufficiency (CVPI), also called Sedlackova syndrome, Shprintzen
syndrome and Velocardiofacial syndrome in the literature, is a special entity among velopharyngeal
insufficiencies. It is featured by hypernasality without overt oropharyngeal anatomical anomalies, therefore
often overlooked clinically. In this study, computer speech lab (CSL) was used to quantitatively analyze
the misarticulation in patients with CVPI, to clarify the particular Chinese formant, the time of vocalism
and the phonetic images, in order to provide a basis for speech therapy of these patients.

Materials and Methods
Twenty-eight cases with CVPI were selected from the Department of Oral and Maxillofacial Surgery,105

Yu et al.

Int Chin J Dent 2003; 3: 105-110.

Ninth People’s Hospital, Shanghai Second Medical University between June 1999 and January 2001.
Among them, 13 were male, 15 were female. Their age ranged from six to 25 years with an average of13.33 years. All the included patients were with normal mentality and audition. They were also proficientin Mandarin Chinese without any speech therapy before. During recording, no patients had common cold,
inflammation of oropharynx and nose, which could affect articulation.
Twenty students from the primary and middle schools of Shanghai served as the control group. Of them,
10 were male and 10 were female. The age range was from six to 19 years with an average of 12.35 years.
No disorders that could influence articulation were found while recording.
The recording room was soundproof room in accordance with the standard of International Acoustics
Association.

CSL4300B was produced by KAY Company, USA. Word Test Table of Phonetics

Intelligibility for Mandarin Chinese was developed by us and accepted nationally.
The patients were in sitting position and relaxed naturally 5 cm away from the microphones. The
following sensitive aspirates /zi/, /ci/, /si/, /ji/, /qi/, /xi/ were practiced five times, and then input into
CSL4300B. The samples collected were 10,000 Hz in frequency, 300 Hz in strip width and 12 in LPC
order. The Pitch, Formant of F1, F2, F3 and Band were measured and averaged. Analysis of variance(ANOVA) was performed using SPSS10.0 software.
The experiment flow was as follows: 1) the subjects, 2) microphone, 3) CSL, 4) preservation of thecollected sound samples, 5) imaging of the tested aspirates, 6) detection, and 7) evaluation.

Results
The acoustic parameters of the selected sounds were shown in Table 1. The comparison of the acoustic
parameters between the control group and CVPI patients was shown in Table 2. The normal sonagram in
human and the sonagram in CVPI patients were shown in Figs. 1 to 4.
From Table 1 and Table 2, it was noted that the differences between the patients group and the controlgroup were principally in F2, B2, F3, and B3 (p<0.05). F2, F3 and VOT in the control group weresignificantly greater than those in the patients group, while B2 and B3 was significantly lower than those in
the patients group. For each aspirate, there was still difference between the two groups.
From Figs. 1 to 4, it could be seen that F1, F2 and F3 in the control group were distinct with fewer
darkness and intensive power. The erected stripes and fills were remarkable, and the time of consonantsphonation was longer. In the patients group, F1 was darker and broader; F2 and F3 were unclear, lower,weaker and broader. Some darker power concentrations were present among formant, resulting in extra
formants. Erected stripes and fills before the vowels of the patients were fewer than those in the controls.

Discussion
Clinical Features of CVPI
CVPI is one kind of velopharyngeal insufficiencies. The clinical manifestations of CVPI are complex,
often accompanying congenital systemic malformations such as inherited cardiovascular disorders.1106

Yu et al.

Int Chin J Dent 2003; 3: 105-110.

Patients usually had aponea1 with the IQ ranging from 55 to 87.2 Most CVPI patients were with anidiosyncratic countenance including eye extenuation, hypercanthus, and bilateral flat suborbit. Fifteen
patients in this report had a typical appearance. Patients with typical countenance resemble each other andseem to have sibship. In 1970s, it was determined to be autosomal dominant heredity with mutation in
22q11. In this series, two patients had congenital cardiovascular diseases concomitantly. The IQ in thisseries was between 44 and 109 with an average of 67, slightly lower than the normal.
Table 1. Acoustic parameters of selected sound.
Sound Sex/zi/M

F/ci/M

F/si/M

F/ji/M

F/qi/M

F/xi/M

FNo.
Normal10CVPI

13Normal

10CVPI

15Normal

10CVPI

13Normal

10

CVPI

15

Normal10

CVPI

13Normal

10

CVPI

15

Normal10

CVPI

13Normal

10

CVPI

15

Normal

10

CVPI

13

Normal

10

CVPI

15

Normal

10

CVPI

13

Normal10

CVPI

15Age (y)Mean 12.95
SD
1.55
Mean 13.79
SD
5.74
Mean 11.37
SD
1.83
Mean 11.86
SD
4.24
Mean 12.95
SD
1.55
Mean 13.79
SD
5.74
Mean 11.37
SD
1.83
Mean 11.86SD4.24
Mean 12.95
SD
1.56
Mean 13.79
SD5.75
Mean 11.37
SD
1.84
Mean 11.86
SD4.25
Mean 12.95
SD1.56
Mean 13.79
SD5.75
Mean 11.37
SD1.84
Mean 11.86
SD
4.25
Mean 12.95
SD1.56
Mean 13.79
SD5.75
Mean 11.37
SD
1.84
Mean 11.86
SD
4.25
Mean 12.95
SD1.56
Mean 13.79
SD5.75
Mean 11.37
SD
1.84
Mean 11.86
SD
4.25

F1 (Hz)B1 (Hz)F2 (Hz)B2 (Hz)B3 (Hz)Pitch (Hz)319.8532.77
303.8625.47
329.6832.57
385.5089.58
347.4242.57
326.9362.80
360.5342.98384.57
89.04
323.8832.90
332.3683.46
355.7958.02
372.9381.46
272.0418.71
286.00**25.50
301.3725.16
343.93**58.20
293.3529.88
290.0026.42
310.2428.53
353.89*67.57
306.0087.81
287.8626.38
321.0332.59
345.32
61.40

59.27
13.85
51.79
18.79
60.58
24.37
81.18
30.91
64.08
12.11
67.14
21.07
71.55
26.13
81.50
37.48
63.50
11.75
63.36
19.30
66.89
25.89
79.89
39.08
47.00
10.58
44.57**
19.05
43.13
21.37
59.43**
21.15
51.46
11.60
48.43
19.89
46.53
23.09
67.93
30.50
52.04
11.05
45.86
22.03
54.66
26.34
63.68
28.18

1,529.12
91.60
1,485.29
418.83
1,743.61
106.53
1,343.18**
439.471,510.50
86.88
1,576.29
445.74
1,758.89
90.15
1,534.57*
385.951,500.85
83.08
1,531.64
427.601,732.53
98.81
1,421.29**
395.512,140.88
140.35
1,414.64**
606.47
2,142.47
512.34
1,546.68**
491.532,071.81
174.951,350.36**
626.672,075.63
538.23
1,441.71**
557.94
2,095.08
123.21
1,333.07**
606.94
2,095.15
369.86
1,425.64**
504.3160.88
2,636.46 76.58
18.74
306.5421.91
128.14** 2,136.07* 112.64 *63.11
205.1738.26
99.55
1,911.82 82.18
44.29
227.7125.70
155.79** 2,186.93* 115.43*
49.54
220.7436.02
65.65
2,682.69 85.50
12.70
185.45
19.55
117.50* 1,923.50**122.50*
39.84
159.11
43.23
113.452,059.00 89.58
40.65
403.9724.08
143.29* 2,215.36 116.50
43.14
301.6634.29
78.69
2,748.27 99.85
11.92
137.9723.75
128.79** 2,079.21 120.43
32.95
329.5032.51
119.13
2,097.97 95.50
37.19
400.1533.90
145.29 * 2,189.71 113.93
41.87
345.5739.34
66.85
2,953.27 92.08
21.30
214.3515.97
163.21** 2,756.79**116.75
44.44
369.4735.77
114.632,582.00 90.21
47.94
232.0025.85
162.142,490.07 114.57
38.45
365.4626.04
85.58
2,918.50 88.19
19.34
204.71
10.46
170.64 ** 2,536.57* 130.79**
50.62
330.7544.50
127.582,775.95 93.13
37.54
335.22
24.55
152.21
2,792.29 126.82
41.07
278.6437.69
96.23
2,931.65 94.27
26.81
190.1813.07
164.50** 2,710.29* 135.43*
44.33
298.4235.67
145.13
2,723.71 106.79
71.69
300.1222.35
144.042,803.39 126.96
44.36
302.5728.45

160.4622.91
192.8661.72
251.5038.37
245.5050.36
156.7723.30
205.5063.51
254.4731.91
248.5041.06
155.92
20.29
186.4258.21
241.3743.64
248.8941.50
157.81
21.51
258.21
27.97
253.8932.06
228.0766.68
156.2321.85
229.21**
66.70
252.5333.44
258.11
23.33
154.73
20.94
206.14*66.33
256.8228.37
245.2938.08

Note: * means, p<0.05; ** means; p<0.01.

107

F3 (Hz)Yu et al.

Int Chin J Dent 2003; 3: 105-110.

Table 2. Comparison of acoustic parameter between the control and CVPI.
Syllable
F1/zi//ci//si//ji//qi//xi/

B1

L

L

F2Male
B2
F3

S
S
S

L
L
L
L
L
L

B3S
S

L
L

S
S
S

L
L
L

Pitch

L
L
L

F1

L
L

B1

L

F2Female
B2

S
S
S
S
S
S

L
L
L

F3

B3

L

L

Pitch

Note: L; The CVPI were larger than the control apparently. S; The CVPI were smaller than the control apparently.

/zi//ci//si//ji//qi//xi//zi/

Fig. 1. Spectrum of normal male.

/zi//ci//si//ji//qi//ci//si//ji//qi//xi/Fig. 2. Spectrum of CVPI male.

/xi//zi/Fig. 3. Spectrum of normal female.

/ci//si//ji//qi//xi/Fig. 4. Spectrum of CVPI female.

CVPI was greatly less common than cleft lip and palate with an incidence of 1/8,000 to 1/5,000.3,4 Thisanomaly is often overlooked clinically, or delayed for appropriate treatment, owing to lack of history of108

Yu et al.

Int Chin J Dent 2003; 3: 105-110.

cleft lip and palate repair, injury of palate, surgery of jaw bones and palatopharyngeal tumor resection. The
main complaints of patients are abnormal vox, mainly hypernasality and hypointelligibility. Many weremisdiagnosed as abnormal articulation caused by poor phonation habits or short lingual frenum, thus
receiving unsuitable managements.
The misarticulation in CVPI patients resulted from too large resonance space during consonant, or too
weak muscle motilities of the soft palate and parapharynx. The conventional examinations for VPI were
almost always compliant to CVPI, and the treatment of CVPI was similar to VPI, too.
The Acoustic Features of CVPI
Everyone has his own characteristic voice, which attributes to the different width, thickness and length ofthe vocal cords, and the variable frequencies. In daily living, the voice between man and woman issignificantly different, because woman has shorter and thinner vocal cords than man, which causes thehigher and sharper voice. In addition, man has a sound tract of different length from woman, which leads
to the different formant frequencies. In 1948, Joos reported that woman has a higher English vocal formant
frequency by 17% than man. In Mandarin Chinese vowels, the formant of woman was 1.25 times as man.
To avoid the bias in the result caused by the above-stated factors, the subjects were divided into groups by
sex to prevent from the interference from sex.
Acoustic analysis extracts major parameters from the sound waves conducted by air from the outside ofsound tract, using appliances to measure and record the phonic acoustics characters, such as clang, pitch,sound power and length, with synthetical study of these parameters. It is a supplement to physiologic
analysis. The test subjects are a serial of phenomenon of the voices sounding that could reflect the position
and method of vocalization.
Clang is decided by the nature of materials and vibratory mode. The distinguishing of clang can be madeby some physical quantities with acoustics characters of voice, such as waveform, the frequency andbandwidth of formant. The bandwidth of formant is defined by that under 3dB of formant. The broader thebandwidth, and the bigger the amplitude, the lower the formant power. Compared to the control, greatdifferences exist both in vowels and consonants in CVPI patients due to nasal leakage and soundcompensation. In view of the acoustic features in vowels, extra formants were found in most sonagrams ofCVPI patients. The mycterophonia formant was superimposed with F1, which was darker and broader.
More extra formants were noted among F1, F2 and F3, making F2 and F3 weaker, broader slurred and withless capacity. The formant frequency of F2 and F3 decreased because of retrusion of the tongue andinsufficient elevation of the soft palate during phonation.
In view of the acoustic features of consonants, because of the palatopharyngeal cleft in CVPI patientsduring phonation, the stripes and fills in sonagrams decreased significantly, or even missing in somepatients. The onset duration of consonants reflecting articulation aspirates also reduced remarkably ordisappeared, presenting weakness or defluxion of the consonants. For example, only /i/, /i/, and /i/ were
heard during phonation of /ji/, /qi/ and /xi/. Pitch is a supersound that could help to distinguish sounds.
The size of tone (namely pitch) was a sense of human being to frequencies of sound signals. It is a109

Yu et al.

Int Chin J Dent 2003; 3: 105-110.

subjective measurement for hearing. The values of pitch were expressed by fundamental frequency ofsound, which is thought to be relevant to the length, healthy status and tensity of the vocal cord. CVPI
patients usually had healthy phonation organs; therefore, there was not difference in pitch compares withthe control.
The differences of acoustic features in CVPI patients were correlated with varied velopharyngeal closure
on one hand, and diverse demands of phonation for velopharyngeal closure on the other hand. This was
supported by the different results from different subjects in this study. The acoustic features of CVPI
patients were fundamentally similar to VPI patients after cleft palate repair, due to approximate sounddisturbance.

References
1. Gorlin RJ, Cohen MM, Levin LS. Syndromes of the head and neck. 3rd Ed. New York: Oxford University Press; 1990. p.
740-2.
2. Golding-Kusher K. Velo-cardio-facial syndromes: Language and psychological profiles. J Craniofac Genet Dev Biol
1985; 5: 259-64.
3. Pike AC, Supper M. Velocardiofacial syndrome. Postgrad Med J 1997; 73(866): 771-5.
4. Pegott RW. Velopharyngeal (speech) disorder (VP(S)D) without overt cleft palate. Am J Plast Surg 1994; 47: 223-9.

Reprint request to:
Dr. Liying Yu
Department of Dentistry, Shanghai Huashan Hospital, Fudan University
Shanghai 200040, P. R. China
Tel: +86-21-62489999
Received on March 12, 2003. Revised on July 25, 2003. Accepted on September 1, 2003.
Copyright ©2003 by the Editorial Council of the International Chinese Journal of Dentistry.

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