• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.2
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• pp.191-205
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• 2000

The purpose of this study was undertaken to determine the effects of orthognathic surgery on speech. The hyposis stated herein is that functional behaviors of the dentofacial complex, such as speech production, may be adversely affected by deviations of a structural nature(especially, Class III malocclusion). Twenty adults with Class III malocclusion(13 female and 7 male) were studied preoperative, immediate postoperative and either 6 or 12 months postoperative lateral cephalograms. They had mandibular prognathism and had undergone mandible setback operation. The position of tongue, soft palate(Uvula), hyoid bone, respiratory track width, and pharyngeal depth were assessed on lateral cephalograms with 23 cephalometric variables, ANOVA, Paired t-tests and Pearson's product-moment correlation coefficient tests were used to evalute the operative changes in all cephalometric parameters. A experienced speech and language pathologists performed narrow phonetic transcriptions of tape-recorded words and sentences produced by each of the ninth patients and the recording tapes were analyzed by phonetic computer program(Computerized Speech Lab(CSL) Model 4300BI(U.S.A.)) These judges also recorded their ratings of each patient's overall consonants, hypernasality, hyponasality, and articulation proficiency. The results obtained are as follows; 1. There were significant changes in distance of posterior pharyngeal wall to tongue (TI-TW2, TS-TW3) after the surgery at 6 months postoperatively(each p<0.01 p<0.05). 2. The posterior tongue point(TI, TS, PPT) moved posteriorly after surgery and remained to its changed position at 6 months postoperatively(p<0.05). The displacement of tongue was correlated with the movement of mandibular setback amount(p<0.05). The hyoid bone moved posteriorly superiorly after immediate postoperative period. There was significant changes in hyoid bone movement after immediated postoperative period(p<0.05), but returned to its original position during the follow-up period(p>0.05) 3. The soft palate was displaced posteriorly superiorly after immediated operative period and remained to its changed position at 6 months postoperatively(p<0.05). ANS-PNS-SPT angle increasing, PPU-PPPo distance narrowing was showed after surgery, and remained its appearance 6 months postoperatively(p<0.05). 4. There were significant changes in formant value and squre diagram of vowel sound after the orthognathic surgery and the follow-up period. There were significant changes in /ㅅ/sound and posterior tongue sound. 5. The posterior movement of tongue and the posteriosuperior movement of soft palate was correlated with mandibular setback amount after orthognathic surgery. On the vowel squre diagram, the author found that the place of articulation after operation moved downward, backward, upward. 6. In assessing speech abnormalities, dental occlusion should be considered as a contributing factor. The vast majority of subjects with preoperative misarticulations eliminated or reduced their errors following orthognathic surgery. There was significant difference in speech impovement between pre- and postoperation.

• The Journal of the Acoustical Society of Korea
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• v.19 no.5
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• pp.60-64
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• 2000

This paper studies the relation between the Fundamental Frequency (F0) and the formants of simple vowels in the Korean language sung by sopranos. It is hewn that, in soprano singing, the F0 of a vowel affects its formants. For this reason the formants of simple vowels sung by sopranos must be considered in all over the soprano singing range. We recorded the five simple vowel sounds /a/, /e/, /i/, /o/, and /u/ sung by five professional sopranos from A3 (220.0Hz) to A5 (880.0Hz) in the major scale and compared the formants of the sung vowels with those of spoken vowels. We observed that F1 and F2 of sung vowels were stable in low F0 (lower than B4) but in high F0 (higher than B4), F1 and F2 lost their stabilities. In the case of /a/, /o/, and /u/, the slope of the F1-F2 graph was about 2.6, and those of the F0-F2 and F0-Fl graphs were 2.2-2.5 and 0.7-1.0, respectively. And as the F0 increases, the F1 and F2 of sung vowels /a/, /e/, /i/, /o/, and /u/ were almost the same. At A5, the Fl and F2 of five sung vowels had the same values. This results suggest that the relation between the F0 and the formants be used to synthesize soprano's singing vowels.

• Phonetics and Speech Sciences
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• v.2 no.3
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• pp.65-73
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• 2010

No systematic study has examined the relationship between acoustic variability and /w/-deletion in Korean. Most previous studies on /w/-deletion have described /w/-variants in categorical terms, i.e., /w/-deletion or a full glide (Silva 1991; Kang 1997; Yun 2005). These studies are based either on impressionistic judgements without a systematic acoustic analysis or on an exclusive examination of internal acoustic variability of /w/ such as F2, without examining the availability of external acoustic cues such as voice onset time (VOT) of a consonant. However, given the important influence of the adjacent sounds for segmental realizations, it is necessary to examine possible acoustic variability in the differentiation of /w/-variants. The present study aims to address this issue by evaluating the acoustic properties of /CwV/, including VOT and formant transitions. In the analysis, 432 tokens in word-initial position (216 /CwV/ words and 216 /CV/ words) were examined. The results indicated that /w/ exhibits four different variants. Firstly, /w/ is realized as a full glide. Such a variant is characterized by a VOT difference and significant differences in F1 and F2 at voicing onset compared with /CwV/ and /CV/. Secondly, /w/ can be maintained but coarticulated with the following vowel. Such a variant is demonstrated by differences in VOT and F2. Thirdly, /w/ is categorically deleted, which is indicated by the absence of any differences in VOT, F1, and F2. Fourthly, /w/ overlaps a consonant. The F2 difference without VOT difference is manifested in the variant. In contrast to VOT, F1, and F2 differences, pitch plays little role in determining /w/-variants in Korean. These findings suggest that allophones can be produced along a gradient continuum of acoustic cues, exhibiting sounds intermediate between the full realization of a given category and its deletion. Furthermore, each variant can be cued by a set of internal and external acoustic cues.

• Proceedings of the KSPS conference
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• 2007.05a
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• pp.143-145
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• 2007

Muscle groups that are located in and around the vocal tract can produce audible changes in frequency and/or intensity of the voice. Vocal vibrato is a characteristic feature in the singing of performers trained in the western classical tradition and vibrato is generally considered to result from modulation in frequency amplitude and timbre. Vocal tremor is also characterized by periodic fluctuations in the voice frequency or intensity and vocal tremor is symptom of a neurological disease as Spasmodic dysphonia , Parkinson's disease. Vocal vibrato and Vocal tremor may have many of the same origins and mechanisms in the voice production systems. The purpose of this study is to find acostic character of Korean traditional song Pansori singer's vibrato and Spasmodic dysphonia patient's vocal tremor. twelve Pansori singers and seven Spasmodic dysponia patients participated to this study. Power spectrum and Real time Spectrogram are used to analyze the acoustic characteristics of Pansori singing and Spasmodic dysphonia patient's voice The results are as follows; First, vowel formant differences between Pansori singing and Spasmodic dysphonia patient's voice are higher F1, F3. Second, The vibrato rate show differences between Pansori singing and Spasmodic dysphonia patients;$4^{\sim}6/sec$ and $5{\sim}6/sec$ Vibrato rate of pitch is 5.7 Hz ${\sim}$ 42.4 Hz for Pansori singing , 3.8 Hz ${\sim}$ 27.9 Hz for Spasmodic dysphonia patients ;Vibrato rate of intensity range is 0.07 dB ${\sim}$ 8.26 dB for Pansori singing and 0.07 dB ${\sim}$ 4.81 dB for Spasmodic dysphonia patients

• The Journal of Internal Korean Medicine
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• v.26 no.3
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• pp.660-669
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• 2005

Objectives : The aim of this study is to find the acoustic characteristics of acupuncture therapy effects on post-stroke dysarthria. Methods : Acupuncture therapy was applied for four to six weeks by inserting needles into eight acupuncture points, CV23, CV24, bilateral 'Sheyu' and ipsilateral ST4, ST6 and contralateral LI4, ST36 on facial palsy side. All the speech samples were collected, pre-treatment and post-treatment, using Computerized Speech Lab. VOT and TD of each speech sample and vowel formant(F1&F2) were analyzed on spectrogram. Result : VOT and TD were decreased after treatment. F1 was decreased, and F2 was increased after treatment. Conclusions : This suggests that acupuncture therapy improves symptoms of post-stroke dysarthria by stimulating articulation organs such as tongue, lips, cheeks, larynx and pharynx.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.1
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• pp.48-58
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• 2001

After performing mandibular setback surgery, we found some changes in patterns and organs of speech. This investigation was undertaken to investigate the aspect and degree of speech patterns according to the amount of surgical setback in mandibular prognathic patients. Thirteen patients with skeletal Class III malocclusion were studied preoperative and postoperative over 6 months. They had undergone the mandible setback operation via bilateral sagittal split ramus osteotomy(BSSRO). We split the patients into two groups. Group 1 included patients whose degree of mandibular setback was 6mm or less, and Group 2 above 6mm. Control group was two adults wish normal speech patterns. A phonetician performed narrow phonetic transcriptions of tape-recorded words and sentences produced by each of the patients and the acoustic characteristics of the plosives, fricatives, and flaps were analyzed with a phonetic computer program (Computerized Speech Lab(CSL) Model 4300B(USA)). The results are as follows: 1. Generally, Patients showed longer closure duration of plosives, shorter VOT(voice onset time) and higher ratio of closure duration against VOT. 2. Patients showed more frequent diffuse distribution than the control group in frication noise energy of fricatives. 3. In fricatives, frequency of compact from were higher in group 1 than in group 2. 4. Generally, a short duration of closure for /ㄹ/ was not realized in the patient's flaps. Instead, it was realized as fricatives, sonorant with a vowel-like formant structure, or trill type consonant. 5. Abnormality of the patient's articulation was reduced, but adaptation of their articulation after surgery was not perfect and the degree of adaptation was different according to the degree of surgical setback.

• Phonetics and Speech Sciences
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• v.12 no.3
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• pp.1-14
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• 2020

Previous studies have confirmed that /o/ and /u/ in Seoul Korean are undergoing a merger in the F1/F2 space, especially for female speakers. As a substitute parameter for formants, it is reported that female speakers use phonation (H1-H2) differences to distinguish /o/ from /u/. This study aimed to explore whether H1-H2 values are being used as perceptual cues for /o/-/u/. A perception test was conducted with 35 college students using /o/ and /u/ spoken by 41 females, which overlap considerably in the vowel space. An acoustic analysis of 182 stimuli was also conducted to see if there is any correspondence between production and perception. The identification rate was 89% on average, 86% for /o/, and 91% for /u/. The results confirmed that when /o/ and /u/ cannot be distinguished in the F1/F2 space because they are too close, H1-H2 differences contribute significantly to the separation of the two vowels. However, in perception, this was not the case. H1-H2 values were not significantly involved in the identification process, and the formants (especially F2) were still dominant cues. The study also showed that even though H1-H2 differences are apparent in females' production, males do not use H1-H2 in their production, and both females and males do not use H1-H2 in their perception. It is presumed that H1-H2 has not yet been developed as a perceptual cue for /o/ and /u/.

• Phonetics and Speech Sciences
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• v.14 no.3
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• pp.87-101
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• 2022

In addition to administering a questionnaire (J-survey), which questions individuals on subjective vocal fatigue, voice samples were collected before and after speech-language pathology sessions from 50 female speech-language pathologists in their 20s and 30s in the Daejeon and Chungnam areas. We identified significant differences in Korean Vocal Fatigue Index scores between the fatigue and non-fatigue groups, with the most prominent differences in sections one and two. Regarding acoustic phonetic characteristics, both groups showed a pattern in which low-frequency band energy was relatively low, and high-frequency band energy was increased after the treatment sessions. This trend was well reflected in the low-to-high ratio of vowels, slope LTAS, energy in the third formant, and energy in the 4,000-8,000 Hz range. A difference between the groups was observed only in the vowel energy of the low-frequency band (0-4,000 Hz) before treatment, with the non-fatigue group having a higher value than the fatigue group. This characteristic could be interpreted as a result of voice abuse and higher muscle tonus caused by long-term voice work. The perturbation parameter and shimmer local was lowered in the non-fatigue group after treatment, and the noise-to-harmonics ratio (NHR) was lowered in both groups following treatment. The decrease in NHR and the fall of shimmer local could be attributed to vocal cord hypertension, but it could be concluded that the effective voice use of speech-language pathologists also contributed to this effect, especially in the non-fatigue group. In the case of the non-fatigue group, the rhamonics-to-noise ratio increased significantly after treatment, indicating that the harmonic structure was more stable after treatment.