• Phonetics and Speech Sciences
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• v.3 no.1
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• pp.135-143
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• 2011

This study evaluated the respiratory capacity of spastic cerebral palsy children who were grouped by GMFCS (Gross Motor Function Classification System) levels and identified the acoustic characteristics of three different types of Korean stops (stop consonants) which are needed for the temporal coordination of larynx and supra-larynx, in these children. Thirty-two children with dysarthria due to spastic cerebral palsy were divided into two subgroups: 14 children classified at GMFCS levels I~III were placed in Group 1 and 18 classified at GMFCS levels IV~V were placed in Group 11, and 18 children with normal speech were selected and placed in the control group. /a/ pronged phonation (sustained vowel /a/) and nine Korean VCV syllables were used. Examined acoustic characteristics were maximum phonation time (MPT) and closure duration and aspiration duration. The results were as follows: 1) The MPTs of the cerebral palsy (CP) groups, both Group I and Group II, were significantly shorter than those of the normal group. 2) The closure durations of the two CP groups were longer than those of the normal group for all 9 target syllables. 3) The aspiration durations of the two CP groups were longer than those of the normal group. 4) The closure duration of the normal and CP Group I was significantly different among tense, aspirated, and lax. However, the CP Group II was different from normal. 5) The aspiration duration of the normal and CP Group I was significantly different among aspirated, tense, and lax. However, the CP Group II was different from normal. 6) The place of articulation influenced less than the manner of articulation on closure and aspiration duration.

• Phonetics and Speech Sciences
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• v.3 no.1
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• pp.125-134
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• 2011

The current study investigated the effects of experience of deaf speech, severity of speaker's articulation, and linguistic cues on speech intelligibility of congenitally deafened adults with cochlear implants. Speech intelligibility was judged by 28 experienced listeners and 40 inexperienced listeners using a word transcription task. A three-way (2 $\times$ 2 $\times$ 4) mixed design was used with the experience of deaf speech (experienced/inexperienced listener) as a between-subject factor, the severity of speaker's articulation (mild to moderate/moderate to severe), and linguistic cues (no/phonetic/semantic/combined) as within-subject factors. The dependent measure was the number of correctly transcribed words. Results revealed that three main effects were statistically significant. Experienced listeners showed better performance on the transcription than inexperienced listeners, and listeners were better in transcribing speakers who were mild to moderate than moderate to severe. There were significant differences in speech intelligibility among the four different types of cues, showing that the combined cues provided the greatest enhancement of the intelligibility scores (combined > semantic > phonological > no). Three two-way interactions were statistically significant, indicating that the type of cues and severity of speakers differentiated experienced listeners from inexperienced listeners. The current results suggested that the use of a combination of linguistic cues increased the speech intelligibility of congenitally deafened adults with cochlear implants, and the experience of deaf speech was critical especially in evaluating speech intelligibility of severe speakers compared to that of mild speakers.

• Phonetics and Speech Sciences
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• v.3 no.1
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• pp.103-110
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• 2011

Idiopathic Parkinson's Disease patients' speech is hypokinetic dysarthria and their speech is possibly the consequence of impaired respiratory support. The purpose of this study was focused on the respiratory characteristics of speech breathing in de novo IPD who were not given prior vocal or anti-Parkinson treatment. A total of 40 subjects participated in the study: 20 de novo IPD patients between the ages of 50 and 80, and 20 normal subjects with similar age, height, and weight matches. Forced Expiratory Vital Capacity (FVC), Forced Expiratory Volume in 1 sec (FEV1) and $FEV_1$ as a percentage of FVC (FEV1/FVC) was measured with a PC-based spirometer (Cosmed). In addition, Maximum Phonation Time (MPT), Mean Airflow Rate (MFR), Subglottal Pressure (Psub) and the number of syllables produced per breath were measured with a Phonatory Aerodynamic System (Kay PENTAX). All subjects were asked to read a standardized Korean paragraph and the following measurements were obtained from the task. Results indicated no statistically significant differences in respiratory function (FEV1/FVC%) and aerodynamic function between the two groups, but the number of syllables per breath was significantly lower in the IPD patient group than in the normal group and it could be predicted by FVC and MFR. Therefore, the study shows that the MFR from the lungs during speech in de novo IPD patients is used inefficiently.

• Phonetics and Speech Sciences
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• v.3 no.1
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• pp.97-102
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• 2011

Electroglottography (EGG) is a common method for providing non-invasive measurements of glottal activity. EGG has been used in vocal pathology as a clinical or research tool to measure vocal fold contact. This paper presents the results of pitch, jitter, and closed quotient (CQ) measurements in electroglottographic signals of young (mean = 22.7 years) and elderly (mean = 74.3 years) male and female subjects. The sustained corner vowels /i/, /a/, and /u/ were measured at around 70 dB SPL since the most notable among EGG variables is the phonation intensity, which showed positive correlation with closed phase. The aim of this paper was to measure EGG data according to age and gender. In CQ, there was a significant difference between young and elderly female subjects while there was no significant difference between young and elderly male subjects. The mean value for young males was higher than that for elderly males while the mean value for young females was lower than that for elderly females. Thus, it can be said that in mean values, increased CQ was related to decreased age for females, while CQ decreased for males as the speaker's age decreased. Although the laryngeal degeneration due to increased age seems to occur to a lesser extent in females, the significant increase of CQ in elderly female voices could not be explained in terms of age-related physiological changes. In standard deviation of pitch and jitter, the mean values for young and elderly males were higher than that for young and elderly females. That is, male subjects showed higher in mean values of voice variables than female subjects. This result could be considered as a sign of vocal instability in males. It was suggested that these results may provide powerful insights into the control and regulation of normal phonation and into the detection and characterization of pathology.

• Phonetics and Speech Sciences
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• v.2 no.2
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• pp.37-42
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• 2010

The purpose of this study is to first discriminate and assess those infants who appear healthy in appearance but who could face possible risk factors in the future and, secondly, to identify those infants who may have difficulties in their developmental stages. The subjects of this study consisted of 35 full-term infants (39-40 weeks) and 33 pre-term infants (34-35 weeks). The infants' voices were recorded for three minutes, for which EDIROL by Roland and a stand-type microphone made by SONY were used. This was done to discern the value of the Breath unit (B-unit) and the fundamental frequencies ($F_0$). It was found that there were significant differences in terms of F0 since the pre-term infants had higher F0 than the full-term infants, showing a result of 436.4 Hz for the full-term infants and 460 Hz for the pre-term infants (p<.05) There was an average rate of 4.01 for the full-term infants and 4.02 (SD=1.69) for the pre-term infants in shimmer. For NHR, it was observed .44 for the full-term infants and .50 for the pre-term infants, thus revealing no significant differences in these observations. This study shows that the crying of newborn babies is related to their physical conditions and it is a sensatory response to these conditions. Furthermore, this study could be helpful for the early detection and measurement of newborn babies who look clinically healthy but could be at risk through acoustic and physiological analyses.

• Phonetics and Speech Sciences
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• v.2 no.2
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• pp.3-16
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• 2010

This study aims at setting the hierarchy of difficulty of the 7 Korean monophthongs for Mongolian learners of Korean according to Prator's theory based on the Contrastive Analysis Hypothesis. In addition to that, it will be shown that the difficulties and errors for Mongolian learners of Korean as a second or foreign language proceed directly from this hierarchy of difficulty. This study began by looking at the speeches of 60 Mongolians for Mongolian monophthongs; data were investigated and analyzed into formant frequencies F1 and F2 of each vowel. Then, the 7 Korean monophthongs were compared with the resultant Mongolian formant values and are assigned to 3 levels, 'same', 'similar' or 'different sound'. The findings in assessing the differences of the 8 nearest equivalents of Korean and Mongolian vowels are as follows: First, Korean /a/ and /$\wedge$/ turned out as a 'same sound' with their counterparts, Mongolian /a/ and /ɔ/. Second, Korean /i/, /e/, /o/, /u/ turned out as a 'similar sound' with each their Mongolian counterparts /i/, /e/, /o/, /u/. Third, Korean /ɨ/ which is nearest to Mongolian /i/ in terms of phonetic features seriously differs from it and is thus assigned to 'different sound'. And lastly, Mongolian /$\mho$/ turned out as a 'different sound' with its nearest counterpart, Korean /u/. Based on these findings the hierarchy of difficulty was constructed. Firstly, 4 Korean monophthongs /a/, /$\wedge$/, /i/, /e/ would be Level 0(Transfer); they would be transferred positively from their Mongolian counterparts when Mongolians learn Korean. Secondly, Korean /o/, /u/ would be Level 5(Split); they would require the Mongolian learner to make a new distinction and cause interference in learning the Korean language because Mongolian /o/, /u/ each have 2 similar counterpart sounds; Korean /o, u/, /u, o/. Thirdly, Korean /ɨ/ which is not in the Mongolian vowel system will be Level 4(Overdifferentiation); the new vowel /ɨ/ which bears little similarity to Mongolian /i/, must be learned entirely anew and will cause much difficulty for Mongolian learners in speaking and writing Korean. And lastly, Mongolian /$\mho$/ will be Level 2(Underdifferentiation); it is absent in the Korean language and doesn‘t cause interference in learning Korean as long as Mongolian learners avoid using it.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.185-192
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• 2010

The acoustic vowel space has been used as an acoustic parameter in dysarthric speech. The aim of this work was to examine mathematical formulae for acoustic vowel space and to apply these to Korean speakers with idiopathic Parkinson's disease(IPD). Five acoustic parameters were chosen from earlier works and one new parameter was proposed, the pentagonal vowel space. The six parameters included triangular vowel space (3 area), irregular quadrilateral vowel space (4 area), irregular pentagonal vowel space (5 area), vowel articulatory index (VAI), formant centralization ratio (FCR) and F2i/F1u ratio (F2 ratio). An experimental group of 32 IPD patients(male:female=16:16) and a control group of twenty healthy people (male:female=8:12) participated in the study and repeated vowels (/a-i-u-e-o/) three times. A correlation analysis was performed among the six parameters, 2-way ANOVA was done with gender and groups as independent factors, and an independent sample t-test was conducted between the male and the female group as post hoc comparison. All parameters were highly correlated with each other and only the FCR showed a high negative correlation with the others. The results of ANOVA showed a significant difference in F2 ratio, 3 area, 4 area and 5 area between gender and in 4 area and 5 area between groups. For the male members of the two groups, significant statistical differences were found in all parameters whereas no such differences were found for the female members. These findings indicated that the vowel space of the female group was wider than the vowel space of the male group. These differences may have been caused by gender-specific speech styles rather than by patho-physiological mechanisms. We also claim that the pentagonal vowel space is better than the other vowel spaces at representing the disordered speech in natural speech situations.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.165-171
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• 2010

Vocal process granuloma can occur commonly by laryngopharyngeal reflux (LPR), vocal abuse or misuse. It has been reported that voice therapy is employed with medication therapy for the patients who has vocal process granuloma, however research about effect of voice therapy can be hardly founded. For that matter, the primary aim of this study was to evaluate the effect of therapeutic method we implement. Thirty one patients who has been diagnosed with vocal process granuloma from January, 2007 to June, 2009 participated in this study. 19 patients among them are provided voice therapy and medication, 12 patients take only medication. Voice therapy is implemented ranging from 5 to 19 sessions (mean: 8.6 sessions). We provided explanation about problem each patient has, voice rest, SKMVTT$^{(R)}$, abdominal breathing, and relaxation in session. All subjects were examined by videostroboscopy, perceptual assessment, acoustic and aerodynamic measures. Consequantly, the greater part of the patients (78.9%) who is treated by voice therapy and medication are confirmed disappearance or decrease of granuloma, it shows better results compared with the group provided only medication (66.7%). Especially, the period of drug administration is 3.7 months in the group runs parallel with voice therapy, the period of other group is 7.8 months. The results of acoustic and aerodynamic measures after treating indicates there are significant decrease in Jitter, Shimmer, and NHR, and increase in MPT, Psub (p<.05). However, there is no large difference statistically even though voice quality has improved since the therapy. In conclusion, it is verified that the voice therapy to the vocal process granuloma patients taking medication is effectual method, we recommend combining voice therapy with medication when treatment is needed for the vocal process granuloma patients.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.119-127
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• 2010

Recently, we have launched a large-scale articulatory study to investigate how the three-way contrastive stops (i.e., lenis, fortis, and aspirated) in Korean are kinematically expressed (i.e., in terms of articulatory movement characteristics) in various contexts, using a magnetometer (Electromagnetic Articulography). In this paper, we report some preliminary results about how the three-way bilabial series /p,$p^h,p^*$/ produced in /Ca/ context in isolation are kinematically characterized not only during the lip closure but also during the following vocalic articulation. Some important notes could be made from the results. First, the degree of lip constriction (as measured by the lip aperture between the upper and lower lips) was smaller for the lenis /p/ and larger for the fortis/aspirated /$p^*,p^h$/, showing a two-way distinction during the closure. Second, the tongue lowering for the following vowel was more extreme after the lenis /p/ than after the fortis/aspirated /$p^*,p^h$/. Regarding this vocalic articulatory difference in the tongue height, we discussed the possibility that the articulatory tension associated with the fortis/aspirated stops is further reflected in the lingual vocalic movement maintaining the tongue position to a certain level for the following vowel /a/, while the lenis consonant does not impose such articulatory constraints, resulting in more tongue lowering. Finally, the temporal relationship between the release of the stop closure and the lowest tongue position of the following vowel remained constant, suggesting that CV coordination is invariantly maintained across the consonant type. This pattern was interpreted as supporting the view that the consonant and vowel gestures are coordinated in much the same way across languages.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.75-82
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• 2010

Many previous studies based on respiratory characteristics of Idiopathic Parkinson's Diseases (IPD) patients have not controlled related factors appropriately. Accordingly, these studies produced discordant results. Furthermore, there is currently a lack of studies that can provide precise explanations on the characteristics of respiration and phonation. This study included a total of 40 subjects: 20 mixed gender de novo IPD patients ranging in age from 50 to 80 (Hoehn & Yahr stage 1~3), and 20 normal subjects with similar matches for age and gender. All participants were controlled based on their gender, age, height, weight, vocal fold function, cognitive abilities, and depression factors. K-MMSE (Korean-Mini Mental State Examination), nVHI-10 (new Voice Handicap Index), and KGDS (Korean Form of Geriatric Depression Scale) were evaluated to select this study subjects. In order to compare respiratory functions between the two groups, FVC, FEV1, and FEV1/FVC were measured using microQuark, a PC-based spirometer. CSL was used by measure MPT and PAS was used to measure MFR. To investigate the characteristics of phonation ability, CSL was used to measure jitter and shimmer, while PAS was used to measure Psub. In order to compare the respiratory function averages and phonation ability between the two groups, statistical analysis was conducted using SPSS (version 12.0). The results of this study showed that most de novo IPD patients were included in the normal average range of respiratory and phonatory ability. But the respiratory and phonatory ability of de novo IPD patients showed lower tendency as compared with the normal group. When the average of respiratory and phonatory ability among the gender was compared, the difference of males was greater than the difference of females.