• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.8 no.2
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• pp.210-216
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• 1997

Many tools have been used to evaluate the voice abnormalities of velopharyngeal insufficiency(VPI). The aim of study was to obtain the objective evaluation method of VPI by comparing the acoustic and nasalance data of experimentally induced VPI group and those of normal control group. Ten healthy young men were included in this study Mild and severe VPI were experimentally induced by retracting velopharyngeal movement. Using the nasometer, we obtained the nasalance score of the sustained oral vowels and those of three types of nasometer passages and the slope scores of nasogram of nasal words. And we analysed the change of formant frequencies for the sustained oral vowels and the changes of various parameters of hyper-tnasality by the computerized speech analysis system. The nasalance score of sustained /a/ was increased significantly in VPI conditions. There was no changes in the slope score of nasogram. On the acoustic speech analysis, the second formant frequencies of vowel /e/ and /i/ were decreased significantly in VPI conditions. This results suggested that the measurement of nasalance score and formant frequency might be useful in the evaluation of VPI.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.14 no.1_2
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• pp.22-39
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• 1992

The purpose of this study was to evaluate hypernasality, nasal air emission, glottal stop, articulation disorder in patients with velopharyngeal incompetency(V.P.I.) and to analyze speech improvement after pharyngoplasty. In this study 61 patients with velopharyngeal incompetency were tested, and in patents with pharyngoplasty speech problems before pharyngoplasty were compared with those after pharyngoplasty. The results obtained are as follows : 1. There are few speech problems in pronouncing the vowel sounds. 2. There are many speech problems in pronouncing the pressure sounds and few speech problems in non-pressure sounds. 3. Speech problems in patients with cleft palate are influenced not by anatomical defect but by severity of velopharyngeal incompetence after palatorrhaphy. 4. Operation methods which decrease the velopharygeal incompetence must be considered for reducing the speech problems. 5. Among the 61 cases with V.P.I. 19 cases(31%) showed nasal air emission and 24 cases(39%) showed glottal stop. 6. Pharyngoplasty is of benefit to primary precipitating components such as hypernasality, nasal air emission but of no benefit to secondary compensating component such as glottal stop. 7. There as no significant difference in speech improvement between pre-and post-pharyngoplasty(p<0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.721-728
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• 2004

Velopharyngeal closure is a sphincter mechanism between the activities of the soft palate, lateral pharyngeal wall and the posterior pharyngeal wall, which divides the oral and nasal cavity. It participates in physiological activities such as swallowing, breathing and speech. It is called a velopharyngeal dysfunction when this mechanism malfunctions. The causes of this dysfunction are defects in (1) length, function, posture of the soft palate, (2) depth and width of the nasopharynx and (3) activity of the posterior and lateral pharyngeal wall. The purposes of this study are to analyze the nasopharynx of cleft palate patients using cephalometry and to evaluate the degree of hypernasality using nasometry to find its relationship with velopharyngeal dysfunction. The following results were obtained : 1. In cephalometry, there were significant differences in soft palate length, soft palate thickness, nasopharyngeal depth, nasopharyngeal area, and adequate ratio between two groups. 2. In nasometry, there were significant differences between two groups in vowel /o/ and sentences including oral consonants. 3. In cleft palate patients, though no general correlation was found between Anatomic VPI and nasalance scores, vowel /i/ and sentences including oral consonants were slightly correlated. In conclusion, cephalometry and nasometer results were significantly different between the two groups. Though in the cleft palate group, Anatomic VPI and nasalance scores, which are indices for velopharyngeal closure, excluding the vowel /i/ and sentences including oral consonants show generally no significance.

• MALSORI
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• v.55
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• pp.45-60
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• 2005

The purpose of this paper is to represent values of acoustic cues for Korean oral stops in the multi-dimensional space, and to attempt to find possible relationships among acoustic cues through correlation analyses. The acoustic cues used for differentiation of 3 types of Korean stops are closure duration, voice onset time and fundamental frequency of a vowel after a stop. The values of these cues are plotted in the two and three dimensional space to see what the critical cues are for separation of different types of stops. Correlation coefficient analyses show that multi-variate approach to statistical analysis is legitimate, and that there are statistically significant relationships among acoustic cues but Oey are not strong enough to make the conjecture that there is a possible relationship among the articulatory or laryngeal mechanisms employed by the acoustic cues.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.1
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• pp.13-20
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• 2006

The articulation disorders associated with velopharyngeal insufficiency (VPI) in cleft palate patients are interested to clinicians particularly. The purpose of this study was to investigate mainly the oropharyngeal air pressure and overall air flow in cleft palate patients. The pressure-measuring catheter was positioned at the midportion of the oropharyngeal cavity with a facial mask. Test words were composed of 9 meaningless polysyllabic words and 17 meaningful words. Aerophone II and Nasometer II were used to measure peak air pressure, mean air pressure, maximum flow rate, volume, phonatory flow rate, nasalance. The data shows that airflow of the cleft palate patient group were higher than those of the control group. Intraoral air pressure of the cleft palate patient group was lower than those of the control group. The first vowel formant and first Bandwidths of the cleft palate patient group were higher than those of the control group.

• Proceedings of the KSPS conference
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• 2005.04a
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• pp.25-28
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• 2005

The purpose of this paper is to represent values of acoustic cues for Korean oral stops in the multi-dimensional space, and to attempt to find possible relationships among acoustic cues through correlation coefficient analyses. The acoustic cues used for differentiation of 3 types of Korean stops are closure duration, voice onset time and fundamental frequency of a vowel after a stop. The values of these cues are plotted in the two and three dimensional space and see what the critical cues are for complete separation of different types of stops. Correlation coefficient analyses show that there are statistically significant relationships among acoustic cues but they are not strong enough to make a conjecture that there is a possible articulatory relationship among the mechanisms employed by the acoustic cues.

• Phonetics and Speech Sciences
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• v.16 no.2
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• pp.37-47
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• 2024

This study was conducted on 27 male students majoring in or preparing for popular music vocals to determine whether they were aware of their voice classification and vocal range. Additionally, differences in the fundamental frequency and average speaking fundamental frequency were compared among the voice classifications. Moreover, considering that they may differ in their ability to produce high frequencies depending on the vowel, differences in voice ranges among the cardinal vowels, /a/, /i/, and /u/, were examined, and differences in voice ranges between vowels were compared by voice classification. The results showed that more than half of the male students majoring in or preparing for popular music vocals were not accurately aware of their voice types. In addition, statistically significant differences were found in the maximum fundamental frequency and frequency range among vowels, indicating differences in the voice range that can be produced depending on the vowel type. In particular, the voice range decreased in the following order: /a/>/u/>/i/. This suggests that while the vowel /a/ is easier to articulate in the high register compared to other vowels, vowels /u/ and /i/ as high vowels involve narrowing of the oral cavity due to the raised position of the tongue, accompanied by raising of the larynx, resulting in a decrease in voice range and difficulty in vocalizing in the high register.

• Speech Sciences
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• v.1
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• pp.237-259
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• 1997

Cleft Palate speech appears to have hyper/hyponasality with velopharyngeal insufficiency and articulation disorders. Previous studies on Cleft Palate speech have shown that speech tends to have lower airflow and air pressure. To examine the aerodynamic characteristics of Cleft Palate speech, Aerophone II Voice function Analyzer was used. We measured sound pressure level, airflow, air pressure and glottal power. Three Cleft Palate adults and five normal adults participated in this experiment. The test words are composed of: (1) the sustained vowel /o/ (2) /CiCi/, where C is one of three different stop consonants in Korean (3) /bimi/. Subjects were asked to produce /bimi/ five times without opening their lips. All the data was statistically tested by t-test for Cleft Palate patients before operation groups and control groups and paired t-test for Cleft Palate patients before and after operation groups. The results were as follow: (1) Cleft Palate patients generally speak with incomplete oral closure and lower oral air pressure. As a result, the SPL of Cleft Palate before operation is 3 dB lower than control groups. (2) Airflow of Cleft Palate in phonation and articulation is lower than that of control groups. However, it increased after operation. Lung volume and mean airflow in phonation are significantly increased (p<0.05). (3) Although velopharyngeal function (velar opening rate) of Cleft Palate is poor in comparison with control groups, it was recovered after operation. In this event maximum flow rate and mean airflow rate are significantly increased (p<0.05). (4) Air pressure of Cleft Palate in speech is lower than that of control groups. In general, the air pressure of Cleft Palate increased after operation. In this event air pressure of glottalized consonant is significantly increased (p<0.04). (5) Glottal Power(mean power, mean efficient and mean resistant) of Cleft Palate patients is lower than that of control groups. But mean efficient and mean resistant of Cleft Palate patients increased significantly (p<0.05) after operation.

• Phonetics and Speech Sciences
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• v.7 no.1
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• pp.21-26
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• 2015

The aim of this study is to synthesize pathological breathy voice and to make a cepstral peak prominence (CPP) table following breathiness ranks by cepstral analysis to supplement reliability of the perceptual auditory judgment task. KlattGrid synthesizer included in Praat was used. Synthesis parameters consist of two groups, i.e., constants and variables. Constant parameters are pitch, amplitude, flutter, open phase, oral formant and bandwidth. Variable parameters are breathiness (BR), aspiration amplitude (AH), and spectral tilt (TL). Five hundred sixty samples of synthetic breathy vowel /a/ for male were created. Three raters participated in ranking of the breathiness. 217 were proved to be inadequate samples from perceptual judgment and cepstral analysis. Finally, 343 samples were selected. These CPP values and other related parameters from cepstral analysis are classified under four breathiness ranks (B0~B3). The mean and standard deviation of CPP is $16.10{\pm}1.15$ dB(B0), $13.68{\pm}1.34$ dB(B1), $10.97{\pm}1.41$ dB(B2), and $3.03{\pm}4.07$ dB(B3). The value of CPP decreases toward the severe group of breathiness because there is a lot of noise and a small quantity of harmonics.

• Phonetics and Speech Sciences
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• v.1 no.3
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• pp.133-144
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• 2009

Pharyngeal flap surgery changes the space and shape of the oral cavity and vocal tract, and these changing conditions bring resonance change. The purpose of this study was to determine the most reliable and valuable parameters for evaluating hypernasality to distinguish two patients before and after pharyngeal flap surgery. Each patient was asked to clearly speak the vowels /a/, /i/, /u/, /e/, /o/ for voice recording. There were nine parameters: Formant (F1, F2, F3), Bandwidth (BW1, BW2, BW3), LPC energy slope ($\Delta$ |A2-A1/F2-F1|), and Band Energy (0-500 Hz, 500-1000 Hz) by each vowel. From the results of discrimination analyses on acoustic parameters, the vowels /a/, /e/ appeared to be insignificant but vowels /i/, /u/, /o/ appeared to be efficient in the separation. A 95%, 100%, and 100% recognition score could be reached when vowels /i/, /u/, and /o/ were analyzed. The results showed that F2, BW3, and LPC slope are more important parameters than the others. Finally, there is a relation between perceptual evaluation score and LPC energy slope of acoustic parameters by least square slope.