• Phonetics and Speech Sciences
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• v.10 no.4
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• pp.67-76
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• 2018

This study was performed to investigate acoustic characteristics of sustained vowels produced by Seoul Korean speakers. For this study, three hundred nine healthy adults were chosen as participants from Korean Standard Speech Database. These subjects were divided into five chronological age groups (20s, 30s, 40s, 50s, 60-70s) and two gender groups (male and female). Fundamental frequency (f0), jitter, shimmer, and NHR (noise-to-harmonics ratio) was measured with 8 Korean vowels (/ɑ/, /æ/, /ʌ/, /e/, /o/, /u/, /ɯ/, /i/) by using Praat. The results showed that the vowel type significantly affected all acoustic parameters. Gender affected f0, jitter, and NHR significantly. The mean female speakers' f0 was greater than the males', and the mean jitter and NHR of male speakers was greater than the females'. Moreover, age affected shimmer and NHR significantly; in particular, the shimmer and NHR of elderly speakers was greater than the young speakers.

• Phonetics and Speech Sciences
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• v.12 no.4
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• pp.57-61
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• 2020

Previous research has indicated that the patterns of phonetic modulations induced by prominence are not consistent across languages but are conditioned by sound systems specific to a given language. Most studies examining the prominence effects in Korean have been restricted to segments in word-initial and phrase-initial positions. The present study, thus, set out to explore the prominence effects for Korean stop consonants in word-medial intervocalic positions. A total of 16 speakers of Seoul Korean (8 males, 8 females) produced word-medial intervocalic lenis and aspirated stops with and without prominence. The prominence was induced by contrast focus on the phonation-type contrast, that is, lenis vs. aspirated stops. Our results showed that F0 of vowels following both lenis and aspirated stops became higher when the target stops received focus than when they did not, whereas voice onset time (VOT) and voicing during stop closure for both lenis and aspirated stops did not differ between the focus and no-focus conditions. The findings add to our understanding of diverse patterns of prominence-induced strengthening on the acoustic realizations of segments.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.33 no.3
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• pp.123-129
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• 2022

Pediatric laryngotracheal stenosis occurs by either congenital or acquired causes and usually indicates subglottic stenosis. The main goals of treatment are decannulation, preserving phonation, and normal swallowing function. Various types and degrees of stenosis and combined anomalies would be the main barriers to reaching successful treatment results unless comprehensive understanding of stenosis. Multidisciplinary team approaches encompassing initial assessment, treatment, and postoperative care, are also necessary to achieve the best treatment outcome. Therapeutic approaches are divided into conservative, endoscopic, and open surgical approaches at length, which are not exclusive to each other. Here, an adequate selection of each therapeutic option and postoperative management will be introduced to achieve decannulation without leaving phonatory or swallowing complications.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.33 no.3
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• pp.183-187
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• 2022

Dysphonia is well known as one of the otolaryngological symptoms of coronavirus disease 2019 (COVID-19) infection. The vocal changes of the COVID-19 condition have been reported in terms of parameters of multi-dimensional voice assessment, including acoustic analysis, auditory-perceptual evaluation, and psychometric assessment. However, there has not been a daily followup study in patients with acute COVID-19 infection. In this study, a 41-year-old male performed daily voice recordings of vowel phonation and passage-reading tasks during the self-quarantine period of one week. Compared to the normal voice status of the prepandemic period, voice abnormalities peaked on day two after the diagnosis of COVID-19 infection and recovered after one week.

• Advances in nano research
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• v.15 no.3
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• pp.239-251
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• 2023

In the present study, we aim to use nanotechnology sensors/actuators to capture pressure and frequency of voice singers and to send signals for improving breathing pressure. In this regard, a circular composite structure having 3 different layers are used. The core layer is nano-composite material reinforced with graphene nanoplatelets. The face sheets are piezo electric materials connected to electrical circuit capable of measuring and applying voltage to the piezoelectric layers. This sensors have extremely smaller size than conventional sensors attached to the neck of singer and, hence, minimizes the influences on the output voice of the singer. A brief theoretical framework are presented for nonlocal strain gradient theory and geometry of the sensor is described in detail. The controlling procedure along with experimental results on 20 amateur and professional singer participants are also presented. The results of the study indicate that the participants could gain benefit from the device for improving their ability in phonation and keeping their frequency at a constant level although they have difficulty in the beginning of the experiment getting used to the device.

• The korean journal of orthodontics
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• v.22 no.1
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• pp.253-271
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• 1992

The purpose of this study was to investigate the difference of EMG activity of the Orbicularis oris and Mentalis muscle between normal occlusion and class III malocclusion group during various lip position and to find out whether any correlations exist between the muscular activity and craniofacial morphology. In this study, 50 subjects with a mean age of 22.9 Years (range 20.0-26.0) were investigated (25 subjects were normal occlusion, and 25 subjects were class III malocclusion). EMG data were recorded from the Orbicularis oris and Mentalis muscle during rest lip posture, lip position at maximum biting, lip position at maximum sealing effort, lip position at chewing, swallowing and phonation with the Medelec MS-25 electromyographic machine. Lateral cephalometric radiographs was taken with the mandible in intercuspal position on all subjects. All data were recorded and statistically processed. The findings of this study can be summerized as follows: 1. In normal occlusion, the maximal mean amplitude of upper lip during the lip position at chewing was lower than that of lower lip and mentalis muscle. But the maximal mean amplitude of orbicularis oris and mentalis muscle during the other lip position was not statistically different. 2. In Class III malocclusion, the maximal mean amplitude of upper lip during the lip position at chewing, swallowing and phonation was lower than that of lower lip and mentalis muscle. But the maximal mean amplitude of orbicularis oris and mentalis muscle during the other lip position was not statistically different. 3. Compare to normal occlusion, the Class III malocclusion was showed low maximal mean amplitude of upper lip during rest lip posture and the lip position at swallowing of saliva, and showed great maximal mean amplitude of lower lip and meantalis muscle during the lip position at chewing and phonation. 4. In normal occlusion, the maximal mean amplitude of upper lip during various lip position was not correlated with the length and thickness of upper lip, but the maximal mean amplitude of lower lip during the lip position at chewing and swallowing was positively correlated with the thickness of lower lip. 5. In Class III malocclusion, the maximal mean amplitude of upper lip during rest lip posture was negatively correlated with the thickness of upper lip, and the maximal mean amplitude of lower lip and mentalis muscle during the lip position at chewing and swallowing was positively correlated with the thickness of lower lip and mentalis muscle. But the maximal mean amplitude of orbicularis oris and mentalis muscle during the other lip position was not correlated with the cephalometric measurements of soft tissue. 6. The correlation between the maximal mean amplitude of orbicularis oris and mentalis muscle and cephalometric measurements of incisors was not nearly present. 7. In normal occlusion, the maximal mean amplitude of lower lip and mentalis muscle during the lip position at maximum biting was negatively correlated with the angle between palatal plane and mandibular plane. In Class III malocclusion, the maximal mean amplitude of upper lip, lower lip and mentalis muscle during function was negatively correlated with the length of maxilla, the maximal mean amplitude of upper lip and lower lip during function was negatively correlated with the SNA and SNPo, and the maximal mean amplitude of lower lip during the lip position at chewing was negatively correlated with the ANB.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.23 no.2
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• pp.129-132
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• 2012

Background and Objectives : MPT is directly related to degree of glottal closure. So it is widely used in the assessment of glottal closure with unilateral vocal fold paralysis. But MPT could be influenced not only by glottal closure but also by pulmonary function. So MPT might not reflect glottal closure in UVFP with decreased pulmonary function. The purpose of the study is to evaluate usefulness of MPT and ratio of /s/ time to /z/ time before and after injection laryngoplasty in UVCP with decreased pulmonary function. Materials and Methods : This study involved 34 patients with unilateral vocal fold paralysis : with decreased pulmonary function in group A (n=15) : with normal pulmonary function in group B (n=19). All patients underwent injection laryngoplasty. Paramters of perceptual analysis, acoustic analysis, aerodynamic analysis, videostroboscopy were compared between two groups. Results : Breathness and asthenic scale, G scale of perceptual analysis were significantly improved in both groups. Glottal gap index were significantly decreased after injection in both groups. In aerodynamic analysis, MPT was improved after injection laryngoplasty in both groups, but S/Z ratio was improved only in group B. In correlation analysis, /s/ time was not correlated with pulmonary function. Conclusion : S/Z ratio reflects neither the pulmonary function nor the glottal clousure properly. MPT is more useful indicator than S/Z ratio to evaluate vocal fold paralysis even with decreased pulmonary function.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.30 no.2
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• pp.112-117
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• 2019

Background and Objectives The purpose of this study was to develop the differential diagnosis scale containing items from adductor spasmodic dysphonia (ADSD) to muscle tension dysphonia (MTD) and the determine clinical utility of newly developed items. Materials and Method The four parts of pitch, redirected phonation, automatic speech and voiced sound were selected for analyzing the characteristics of ADSD in the literature. One part of tense voiceless sound was developed according to the Korean manner of articulation. The content validity was evaluated based on 5 scales (1-5 point) analysis from 30 experts. One hundred patients (50 ADSD and 50 MTD) were recorded in reading a sentence and sustained phonation. The two speech language pathologist evaluated recorded voices through a blind test using 4 scales (0-3 point) for newly developed items. Results As a result of verifying the content validity of items with experts, it was identified that the differentiated items were valid with 4.2 out of 5. Through the differential diagnosis between two groups according to the items, the correlation between sub-domains and total scores was shown as higher than 0.710. The result of analyzing the reliability on each diagnosis domain was 0.840-0.893, which showed the internal consistency of items was great. Newly developed five parts of ADSD were significantly higher than those of MTD with strong correlation (p<0.01). The reliability among the evaluators was analyzed as high with 0.892. Conclusion In this study, the differential diagnosis scale of ADSD was revealed as having validity and reliability. It is considered that it will be useful for differentiating ADSD and MTD in the clinical field.

• The Journal of the Korea Contents Association
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• v.17 no.11
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• pp.156-166
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• 2017

The purpose of this study was to evaluate the effect of the tongue's maximum resistance training program on the accuracy of the tongue training program using the Iowa Oral Performance Instrument (IOPI) and to compare the effects of tongue muscle strength and spoken language function on objective function. The experiment was diagnosed with stroke hemiplegia divided into tongue pressure strength and accuracy training therapy group and the oromotor exercise therapy group Anterior Tongue Pressure(ATP), Posterior Tongue Pressure (PTP), and Posterior Tongue Pressure (PTP) were measured before and after the intervention to evaluate changes in tongue strength and verbal ability. Maximum Phonation Time (MPT). The results of this study are as follows. There was no significant difference in tongue strength and verbal function between training group and oral facial exercise group. There was no significant difference between tongue strength training and oral facial exercise group. Therefore, it was shown that the tongue pressure strength and accuracy training therapy group was not effective to improve tongue muscle strength and spoken language ability than the oromotor exercise therapy group.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.10 no.1
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• pp.5-11
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• 1999

Background and Objectives : Recently, many people suffering from voice change visit otolaryngologist. So, it is important to study vocal function in patients with glottic or laryngeal disease. Aerodynamic investigation is valuable information about the efficiency of the larynx in translating air pressure to acoustic signal. The purpose of this study was to investigate the aerodynamic data in patients with vocal polyp, compare this data with that of the normal Korean. Materials and Methods : In aerodynamic study, maximum phonation time, mean air flow rate, phonatory flow volume and subglottal pressure were tested by using Aerophone II voice function analyzer in 157 normal korean and 143 patients with vocal polyp, aged from 20 to 69 years randomly selected. Results and Conclusion : In vocal polyp, maximum phonation time was significantly decreased and mean air How rate was increased. Phonatory flow volume was significantly decreased and subglottic pressure was increased only in female with vocal polyp. These data will be served as basic data of evaluation after treatment and postoperative assessment of the patients with vocal polyp.