• Phonetics and Speech Sciences
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• v.7 no.1
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• pp.79-86
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• 2015

This study explored the vowel effect on acoustic perturbation measures in voice quality analysis. For this study, the perturbation parameters (%jitter, %shimmer) and noise parameter (SNR) were measured with 7 Korean vowels (/a/, /ɛ/, /i/, /o/, /u/, /ɯ/, /ʌ/) using CSpeech with 50 Korean normal young adults (24 males and 26 females). A significant vowel effect was found only in %shimmer and in particular, low-back /a/vowel was significantly different from other vowels in %shimmer. The least perturbation and noise were exhibited on high-back /ɯ/ and /o/ vowel, respectively. Based on tongue height, a significant higher %shimmer was demonstrated on low vowels than high vowels. In addition, back vowels in tongue advancement and rounded vowels in lip rounding showed significantly less perturbation and noise. The least variability of perturbation and noise within individuals was demonstrated on the vowel /i/ in three repeated measures. However, there was no significant difference among 3 token measures in single session among vowels tested except the vowel /o/. Consequently, the vowel /a/ commonly used in acoustic perturbation measures exhibited higher perturbation and noise whereas higher stability and less variability were demonstrated on the high-back vowel /u/. These results suggested that the Korean high-back vowel /u/ can be more appropriate and reliable for perturbation acoustic measures.

• Phonetics and Speech Sciences
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• v.7 no.1
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• pp.67-77
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• 2015

The purpose of this study was to investigate how deaf parents influence the speech sounds of their normal-hearing children. Twenty four normal hearing children of deaf adults (CODA) and normal hearing parents (NORMAL) aged 3 to 4 participated in the study. The F1, F2, and the vowel triangle area in 7 vowels and the voice onset times (VOTs) and closure durations in 9 stops were measured. The results of the study are as follows. First, the F1 and F2 for all vowels were higher and the vowel triangle area was larger in CODA than in NORMAL although they were not statistically significant. Second, VOTs in $C_{stop}V$ for $/t^*/$ and in $VC_{stop}V$ for $/t^*/$, $/t^h/$, and $/k^h/$ were longer in CODA than in NORMAL. Most stops in CODA appeared to be longer VOTs for most phonemes. Third, the manner and place of articulation in stops did not make a difference between CODA and NORMAL in VOTs and closed durations. CODA does not demonstrate the speech characteristics of deaf people, however, they seem to speak differently than NORMAL, which means CODA might be influenced by a different linguistic environment created by deaf parents in some way.

• Phonetics and Speech Sciences
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• v.7 no.1
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• pp.39-45
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• 2015

Changes in speech production in normal elderly might be subtle and gradual. Therefore, an acoustic analysis is appropriate to identify the effect of aging on speech. For this purpose, this study examined four speech parameters; voice onset time (VOT), VOT range, $f_0$ of following vowel($f_0FV$), and $f_0FV$ difference in two age groups, old (mean age 74.57 yrs.) and young (m: 27.43 yrs.). The results show that compared to the older group the younger demonstrated significantly shorter VOTs in lenis and longer in aspirated stop. VOT ranges were relatively broad and consequently overlapped between the phonation types (e.g., lenis, fortis, aspirated). The $f_0FV$ values in the older group which are an integral parameter with VOT were lower compared with the young group. The $f_0FV$ differences in the old female group were significantly narrower than the young female group, therefore, clear distinction became difficult. In conclusion, contrast in temporal information was obscured, and the domain of glottal information was diminished on stop consonants in Korean elderly. The findings suggest that central/peripheral changes by aging could lead to a deficit in coordination between phonation and articulation.

• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.103-111
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• 2013

Traditionally it has been assumed that written abilities are completely dependent on phonology. Therefore spoken and written language skills in aphasic patients have been known to exhibit similar types of impairment. However, a number of latest studies have reported the findings that support the orthographic autonomy hypothesis. The purpose of this study was to examine whether fluent aphasic patients have discrepancy between speaking and writing skills, thereby identifying whether the two skills are realized through independent processes. To this end, this study compared the K-FAST speaking and writing tasks of 30 aphasia patients. In addition, 16 aphasia patients, who were capable of producing sentences not only in speaking but also in writing, were compared in their performances at each phase of the sentence production process. As a result, the subjects exhibited different performances between speaking and writing, along with statistically significant differences between the two language skills at positional and phonological encoding phases of the sentence production process. Therefore, the study's results suggest that written language is more likely to be produced via independent routes without the mediation of the process of spoken language production, beginning from a certain phase of the sentence production process.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.91-98
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• 2013

This study investigates the difference in the evaluation of foreign-accentedness of English pronunciation across subject groups, evaluated accents, and compared components. This study independently evaluates the prosody and segmentals of the foreign-accented English sentences by pairwise difference rating. Using the prosody swapping technique, segmentals and prosody of the English sentences read by native speakers of American English (one male and one female) were combined with the corresponding segmentals and prosody of the English sentences read by male and female native speakers of Chinese, Japanese or Korean (one male and one female from each native language). These stimuli were evaluated by 4 different subject groups: native speakers of American English, Korean, Chinese, and Japanese. The results showed that the Japanese subject group scored higher in prosody difference than in segmental difference while the other groups scored the other way around. This study is significant in that the attitude toward the difference in segmentals and prosody of the foreign accents of English varies with the native language of the subject group. In other words, for native speakers of some languages, the difference in prosody could have a greater influence on the foreign-accentedness than the difference in segmentals, while for native speakers of other languages the other way around.

• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.95-101
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• 2013

Aging is related to anatomical and physiological changes in respiratory and phonation organs. These changes influence articulation which leads to inaccurate speech and slow articulatory diadochokinesis(DDK). DDK indicates the range, rate, regularity, accuracy, and agility of articulation that reflect motor speech function. The purpose of this study is to investigate the rates and regularities of DDK in healthy Korean elderly through passive acoustic analysis (Praat). Thirty subjects between the ages of 65 and 94 participated in this study. Rate was observed for 5 seconds, while regularity was calculated based on the standard deviation on the following: 1) syllable duration of each task; 2) gap duration between syllables. Then, simple regression analysis was conducted in order to examine the effect of age on performance. The result showed that the slow rate was not a significant factor in terms of advancing age. Furthermore, regularity indicated a significant difference in the following: 1) /pʌ/, /kʌ/ and /pʌtʌkʌ/ in syllable duration; 2) /kʌ/ duration in the gap between syllables. In conclusion, articulatory coordination is reduced with the onset of aging. In particular, /kʌ/ would be a sensitive task for articulatory coordination.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.81-90
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• 2013

This study explored how Korean L2 learners of English utilize multiple acoustic cues (VOT and F0) in perceiving and producing the English alveolar stop with a voicing contrast. Thirty-four 18-year-old high-school students participated in the study. Their English proficiency level was classified as either 'high' (HEP) or 'low' (LEP) according to high-school English level standardization. Thirty different synthesized syllables were presented in audio stimuli by combining a 6-step VOTs and a 5-step F0s. The listeners judged how close the audio stimulus was to /t/ or /d/ in L2 using a visual analogue scale. The L2 /d/ and /t/ productions collected from the 22 learners (12 HEP, 10 LEP) were acoustically analyzed by measuring VOT and F0 at the vowel onset. Results showed that LEP listeners attended to the F0 in the stimuli more sensitively than HEP listeners, suggesting that HEP listeners could inhibit less important acoustic dimensions better than LEP listeners in their L2 perception. The L2 production patterns also exhibited a group-difference between HEP and LEP in that HEP speakers utilized their VOT dimension (primary cue in L2) more effectively than LEP speakers. Taken together, the study showed that the relative cue-weighting strategies in L2 perception and production are closely related to the learner's L2 proficiency level in that more proficient learners had a better control of inhibiting and enhancing the relevant acoustic parameters.

• Phonetics and Speech Sciences
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• v.5 no.3
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• pp.83-93
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• 2013

Vocal hygiene education is an indirect training approach to improve vocal function by educating all facets of optimal vocal health. Satisfaction levels of participants might be an important component of this indirect therapy for voice disorders. The authors aimed to investigate the satisfaction levels of vocal hygiene education in 51 patients with voice problems. We classified voice disorders of the participants according to three etiological categories (subgroups): organic, neurogenic, and functional. The survey consisted of three parts: 1) a condition of vocal hygiene education, 2) a degree of satisfaction of the present education, and 3) a request for future education. Participants responded to each item of the survey using a five-point Likert scale of 1 to 5 (1 being not at all and 5 being extremely). They also wrote down personal comments of improvement. Participants scored the vocal hygiene education offered by the speech-language pathologists between '3' and '4'. Specifically, the participants were highly satisfied with the specific and comprehensible explanation/instruction given by their speech-language pathologists. However, they were less satisfied with the tuition fee for the therapy sessions. Vocal hygiene education is offered individually to people in a clinical setting. Our results support the notion that vocal hygiene education can be an integral aspect of the treatment of voice problems in most cases.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.71-78
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• 2013

The purpose of this study was to compare the acoustic voice outcomes of children with cochlear implant to those of children with normal hearing. Participants were 41 children using unilateral cochlear implant (18 males and 23 females), and children with normal hearing from the same age and sex. Mean age of implantation was approximately 3 years old, mean duration of implant use was 4 years in CI group. Acoustic analyses were performed using MDVP of CSL. Speech samples were 3 sustained vowels, /a, i, u/. 9 parameters (F0, Fhi, Flo, Jitter, Shimmer, vF0, vAm, NHR, and SPI) were analyzed. Children with CI did not show the significant differences in those parameters after the vowel /a/ phonation. Meanwhile, there were significantly different results in F0, Fhi, vF0, and SPI after /i, u/ phonation. These results revealed that differences of voice characteristics in children with CI compare to children with NH persist regarding vowel context. It suggests that high vowels would recommend as speech samples for acoustic evaluation. Futhermore perceptual analysis and speech therapy for phonation control would be necessary for children with CI.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.53-61
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• 2013

Voice disorders are most common in female teachers due to work-related vocal demands; however, only a few studies tried to evaluate individual risk factors with work-related risk factors to diagnose voice disorders. This study evaluated sixty-seven female elementary teachers (36 with voice disorders and 31 without voice disorders) to compare their vocal misuse, overuse, and vocal hygiene behaviors. Total Voice Handicap Index scores and VHI subscale (P, E, F) scores were not significantly different between two groups (p>0.05) and there was no relationship between VHI and acoustic measures (p>0.05). Loud talking, talking in noisy situations, and excessive speaking were significantly more frequent in female teachers with voice disorders (p<0.05) and thereby these overuse and misuse behavioral patterns were identified as risk factors to develop voice disorders in female teachers. Also, hydration was the most common behavior for vocal hygiene when experiencing vocal fatigue; however, hydration with hot green tea or coffee and throat clearing were often misused for vocal hygiene. This study found that female teachers from both groups presented higher voice handicap regardless of voice disorders. This study suggests a multidimensional voice assessment protocol is required to reflect voice problems in teachers and a vocal education program may be important to improve vocal hygiene knowledge and behavioral changes in female teachers.