• Phonetics and Speech Sciences
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• v.5 no.1
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• pp.63-69
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• 2013

This study attempted to investigate the characteristics of Phonation Threshold Pressure and Phonation Threshold Airflow of Patients who have Functional voice disorder. 50 subjects participated in study (32 subjects were patients who had functional voice disorders and 20 subjects were normal adults). The PAS (Phonatory aerodynamic system, model 6600, KAY electronics, Inc.) was used to measure the data and to do the analysis. Data from the Phonation Threshold Pressure was measured using voicing efficiency of the PAS protocol. Data from the Phonation Threshold Airflow was measured using Maximum Sustained Phonation of the PAS protocol. Those were used because of the ease of phonation. The results of this study showed that the differences in Phonation Threshold Pressure and Phonation Threshold Airflow between patients who had functional voice disorder and normal adults could be significant index. Patients who had functional voice disorder showed more higher figures than normal adults. These results suggest that Phonation Threshold Pressure and Phonation Threshold Airflow are very useful in diagnosing the voice disorder. The measured data also provided useful information for diagnosing patients with vocal fold diseases.

• Phonetics and Speech Sciences
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• v.5 no.1
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• pp.39-46
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• 2013

This study examined the effects of phonetic complexity and articulatory severity on Percentage of Correct Consonant (PCC) and speech intelligibility in adults with dysarthria. Speech samples of thirty-two words from APAC (Assessment of Phonology and Articulation of Children) were collected from 38 dysarthric speakers with one of two different levels of articulatory severities (mild or mild-moderate). A PCC and speech intelligibility score was calculated by the 4 levels of phonetic complexity. Two-way mixed ANOVA analysis revealed: (1) the group with mild severity showed significantly higher PCC and speech intelligibility scores than the mild-moderate articulatory severity group, (2) PCC at the phonetic complexity level 4 was significantly lower than those at the other levels and (3) an interaction effect of articulatory severity and phonetic complexity was observed only on the PCC. Pearson correlation analysis demonstrated the degree of correlation between PCC and speech intelligibility varied depending on the level of articulatory severity and phonetic complexity. The clinical implications of the findings were discussed.

• Phonetics and Speech Sciences
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• v.5 no.1
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• pp.27-38
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• 2013

Healthcare providers in Korea are using conservative pharmacological treatment for Alzheimer's disease (AD) to delay the progress of the disease or to mitigate its behavioral and neurological symptoms. However, there is a growing need for interventions using practical non-pharmacologic treatment, as the effects of pharmacological treatments has faced limitations. This research provided a cognitive rehabilitation program to 3 AD patients and used a multiple baseline design across subjects to examine the effects. Performing reality orientation therapy (ROT) for 1 cycle (4 weeks) resulted in a slight increase in accuracy and responsiveness on an orientation task, mainly with patients with mild cases of AD. Also, in the sub-domain of the Korean-Mini Mental Status Examination performed to examine changes in cognitive ability, there were minimal changes in place orientation. In functional communication, however, there were no significant differences before and after the intervention. In conclusion, we found that ROT was an effective intervention for improving accuracy and responsiveness in the orientation of patients with mild cases of AD. In future studies, the effect of non-pharmacological interventions can be evaluated more reliably by examining the interaction effects of sample size, length of the intervention, outcome measurements, and pharmacological intervention.

• Phonetics and Speech Sciences
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• v.5 no.1
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• pp.19-26
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• 2013

The aerodynamic characteristics (subglottal pressure (Ps) and mean airflow rate (MFR)), fundamental frequency (Fo), intensity (I), vocal efficiency (VE), and closed quotient (CQ) were compared during a sustained vowel /o/ sound under three conditions: in a comfortable loudness and pitch level (condition 1), in a maximum loudness level with a fixed pitch (condition 2), and in a maximum loudness level without a fixed pitch (condition 3). Also, multiple regression analyses were done to measure the aerodynamic characteristics affect on the VE and the CQ in each condition. The results showed the Fo, Ps, MFR, VE, and CQ increased as I increased with and without fixed pitch. Most notably, VE in condition 3 was the highest of all the conditions, but CQ was not very high. By the results of multiple regression analysis, VE was significantly affected by I and Ps in all conditions; Fo was the other main key for affecting VE in high pitch. However, none of the aerodynamic characteristics significantly affected CQ. As I increases, Fo should be increased by increasing Ps and VE. Therefore, researchers should consider and specify an a priori to Fo, Ps, and I when measuring VE to examine the complex and delicate vocal mechanism.

• Phonetics and Speech Sciences
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• v.8 no.4
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• pp.131-138
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• 2016

This study analyzes the characteristics of good impression using speech manipulation scripts and investigates the characteristics of preferred speech voice. Fourty male and female college students participated in this study. They have been exposed to the Gyeongsang dialect spoken by their friends and family for more than 15 years. Two sample voices(1 male and 1 female), considered as giving good impression, were subject to voice analysis. Two students were asked to read the sample paragraph of 'Walking' and their voice samples were analyzed through Praat. The collected speech data were manipulated into 4 different sets by changing pitch level, degree of loudness and speech rate. First, both men and women received good impression more from pitch-lowered sound than from the original one. Second, men tended to receive good impression more from slightly louder voice than from the natural-pitched one. Third, it was shown that men often felt more drowned to a voice at slightly faster speech rate than at the original speech rate. Overall, both male and female listeners favored lower pitch over the original pitch. Men tended to prefer louder voice sound while women preferred less loud one. Men received better impression at a lower speech rate but women at a faster speech rate.

• Phonetics and Speech Sciences
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• v.8 no.4
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• pp.63-69
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• 2016

Twenty five English native speakers with two different L2 experienced groups and nineteen native Koreans heard both Korean word-initial nasals (/m/ and /n/) in three vowel contexts (low, mid, and high) produced by a native Korean speaker. The experiment examined the hypothesis that Korean nasals are more likely to be judged or perceived correctly by the L2-experienced English learners of Korean than the unexperienced counterparts. The result showed that L2 experienced group was more sensitive to effects of vowel height in judging the Korean nasals in which the perception of nasals before the high vowels was more subject to it. In addition, place of nasal articulation causes asymmetry relations - bilabial nasal /m/ is more likely to be perceived as plosives rather than alveolar nasal /n/. The study found that the L2 experience has a somewhat limited role in perceiving the nasals correctly in the word-initial position, especially before the high vowels, in that even the L2 experienced English subjects have difficulty in identifying the Korean nasals correctly in this environment. Nevertheless, low L2 proficiency might be accounted for the difficulty in the bilabial nasal identification observed by the L2 experienced group.

• Phonetics and Speech Sciences
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• v.8 no.4
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• pp.71-78
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• 2016

The purpose of this study is to investigate the effect of Japanese(L1) on the production of Korean accentual phrases(L2). Korean and Japanese have a similar prosodic structure. But different from Korean, Japanese is a pitch accent language. So each word has its own pitch accent. And pitch accents are maintained in the sentence intonation. This difference will have a negative influence on the production of Korean sentence intonation. For this study 4 Korean natives speakers and 10 advanced Japanese learners of Korean participated in the production test. The material analysed constituted 11 Korean sentences, six of which contain formally identical Sino-Korean and Sino-Japanese words. The results show that the initial pitch pattern of Korean accentual phrases was affected by Japanese pitch accent types and this interference was greater for formally identical Sino-Korean and Sino-Japanese words. But besides initial tones of accentual phrase, some positive interference was observed in the internal tonal pattern of accentual phrase. In the phonetic realization, the internal pitch range and initial pitch rising of accentual phrases was greater for Japanese learners of Korean than native speakers of Korean.

• Phonetics and Speech Sciences
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• v.8 no.4
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• pp.31-38
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• 2016

The purpose of the current study was to examine the acquisition of the second language prosody by Korean learners of English. Specifically, this study investigated Korean learners' patterns of prosodic phrasing and their use of edge tones (i.e., phrase accents and boundary tones) in English, and then compared the patterns with those of native English speakers. Eight Korean learners and 8 native speakers of English read 5 different English passages. Both groups' patterns of tones and prosodic phrasing were analyzed using the Mainstream American English Tones and Break Indices (MAE_ToBI) transcription conventions. The results indicated that the Korean learners chunked their speech into prosodic phrases more frequently than the native speakers did. This frequent prosodic phrasing pattern was especially noticeable in sentence-internal prosodic phrases, often where there was no punctuation mark. Tonal analyses revealed that the Korean learners put significantly more High phrase accents (H-) on their sentence-internal intermediate phrase boundaries than the native speakers of English. In addition, compared with the native speakers, the Korean learners used significantly more High boundary tones (both H-H% and L-H%) for the sentence-internal intonational phrases, while they used similar proportion of High boundary tones for the sentence-final intonational phrases. Overall, the results suggested that Korean learners of English successfully acquired the meanings and functions of prosodic phrasing and edge tones in English as well as that they are able to efficiently use these prosodic features to convey their own discourse intention.

• Phonetics and Speech Sciences
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• v.8 no.4
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• pp.89-95
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• 2016

The purpose of this work is to analyze and synthesize the pseudo-periodicity of voice using a source model. A speech signal has periodic characteristics; however, it is not completely periodic. While periodicity contributes significantly to the production of prosody, emotional status, etc., pseudo-periodicity contributes to the distinctions between normal and abnormal status, the naturalness of normal speech, etc. Measurement of pseudo-periodicity is typically performed through parameters such as jitter and shimmer. For studying the pseudo-periodic nature of voice in a controlled environment, through collected natural voice, we can only observe the distributions of the parameters, which are limited by the size of collected data. If we can generate voice samples in a controlled manner, experiments that are more diverse can be conducted. In this study, the probability distributions of vowel pitch variation are obtained from the speech signal. Based on the probability distribution of vocal folds, pulses with a designated jitter value are synthesized. Then, the target and re-analyzed jitter values are compared to check the validity of the method. It was found that the jitter synthesis method is useful for normal voice synthesis.

• Phonetics and Speech Sciences
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• v.8 no.4
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• pp.103-113
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• 2016

This paper aims to propose articulatory features as novel predictors for automatic pronunciation assessment of English produced by Korean learners. Based on the distinctive feature theory, where phonemes are represented as a set of articulatory/phonetic properties, we propose articulatory Goodness-Of-Pronunciation(aGOP) features in terms of the corresponding articulatory attributes, such as nasal, sonorant, anterior, etc. An English speech corpus spoken by Korean learners is used in the assessment modeling. In our system, learners' speech is forced aligned and recognized by using the acoustic and pronunciation models derived from the WSJ corpus (native North American speech) and the CMU pronouncing dictionary, respectively. In order to compute aGOP features, articulatory models are trained for the corresponding articulatory attributes. In addition to the proposed features, various features which are divided into four categories such as RATE, SEGMENT, SILENCE, and GOP are applied as a baseline. In order to enhance the assessment modeling performance and investigate the weights of the salient features, relevant features are extracted by using Best Subset Selection(BSS). The results show that the proposed model using aGOP features outperform the baseline. In addition, analysis of relevant features extracted by BSS reveals that the selected aGOP features represent the salient variations of Korean learners of English. The results are expected to be effective for automatic pronunciation error detection, as well.