• Phonetics and Speech Sciences
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• v.2 no.2
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• pp.51-60
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• 2010

This study is to examine how Korean speakers realize English stress on the homographic words. Experiments were performed by Korean speakers three times, before stress instruction, immediately after instruction, and six weeks after instruction. First, duration, fundamental frequency, and intensity of the vowel in a stressed syllable of three homographic words produced by Korean speakers were compared with those of native speakers of English. The result shows that when the words were used as nouns, before instruction Korean speakers had shorter duration and lower fundamental frequency in the stressed vowel than the native speakers, which indicates that Korean speakers did not assign the primary stress on the first syllable of the nouns. After instruction, the values of duration and fundamental frequency were increased and the differences between two groups were decreased. Next, the values of these stress features measured three times were analyzed in order to find out how they changed through instruction. The analysis shows that after instruction the values of three features were increased compared to the ones before instruction, and that the biggest change was in duration of the vowel and the next was fundamental frequency. Six weeks after instruction, the values of duration and intensity were decreased than those immediately after instruction. This means that instruction is helpful for Korean speakers to assign the stress for the English homographic words, and that instruction and practice are needed repeatedly.

• Phonetics and Speech Sciences
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• v.2 no.2
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• pp.43-50
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• 2010

English vowels can be divided into monophthongs and diphthongs depending on the number of vocal tract shapes. Diphthongs are usually produced with more than one shape. This study attempts to collect acoustical data of English diphthongs published by Hillenbrand et al.(1995) online and to examine acoustic features of the diphthongs for phoneticians and English teachers. Sixty three American males and females were chosen after excluding those subjects with different target vowels or ambiguous formant tracks. The author used Praat to obtain the acoustical data systematically at eleven equidistant timepoints over the diphthongal segment. Obvious errors were corrected based on the spectrographic display of each diphthong. Results show that the formant trajectories of the diphthongs produced by the American males and females appeared quite similar. When the female formant values were uniformly normalized to those of the males, almost a perfect collapse occurred. Secondly, the diphthongal movements on the vowel space appeared not linear due to the coarticulatory gesture for the following consonant. Thirdly, the average duration of the diphthongs produced by the females was 1.156 times longer than that of the males while the pitch ratio between the two groups turned out to be 1.746 with a similar contour over measurement points. The author concludes that English diphthongs produced by various groups can be compared systematically when the acoustical values are obtained at proportional timepoints. Further studies will be desirable on the comparison of English diphthongs produced by native and nonnative speakers.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.229-238
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• 2010

This study investigates the differences in acoustic parameters in vowel space across hearing loss, gender and vowels. The parameters include F1, F2, Euclidean Distance between vowels, and vowel triangular area comprised of /i/, /a/ and /u/. For this study, 20 hearing-impaired and normal hearing adults as a control group were asked to read 7 Korean vowels (/a, $\wedge$, o, u, w, i, $\varepsilon$/). Subjects' readings were recorded by NasalView and analyzed by Praat. Results showed that F1 were significantly higher in the hearing impaired group than in the normal hearing group, higher in the female group than in male group, and higher in low vowels than in high vowels. And the means of F2 was significantly higher in the hearing impaired group than in normal hearing group, higher in high vowels than in low vowels, and there was no difference between male and female group. Secondly, Euclidean distance between vowels was significantly shorter in the hearing-impaired group than in the normal group. Finally, acoustic vowel space area was significantly smaller in the hearing-impaired group than in the normal hearing group. The hearing-impaired group showed that front vowels tended to be backed and back vowels to be fronted.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.223-228
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• 2010

This study investigated the closed quotient and other voice quality parameters using electroglottography (EGG) in sustaining the vowel /a/ and reading a sentence at the comfortable pitch and loudness in healthy Korean adults. Seventy two healthy adults (36 men, 36 women) aged 20~40 years were included in the study. The tasks were recorded and analyzed using Lx Speech Studio. In vowel sustaining task, closed quotient (Qx), fundamental frequency (Fx), sound pressure level (SPL), Jitter, and Shimmer were measured. In sentence reading task, closed quotient (DQx), fundamental frequency (DFx), and sound pressure level (DAx) were measured. The sex effects were observed on Qx, Fx, Shimmer, DQx, and DFx. Men had significantly higher Qx and DQx than women, but had significantly lower Shimmer than women. However, there was no sex effect on Jitter. The task effects on Qx and SPL as well as DQx and DAx were also assessed. Qx and SPL were significantly higher than DQx and DAx in both gender. This study showed that the closed quotients in both vowel sustaining and sentence reading tasks were significantly related to other voice quality parameters. Therefore, clinicians and researchers should describe the voice quality parameters like fundamental frequency, sound pressure level, Jitter, Shimmer, and so on when reporting closed quotients using EGG.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.109-118
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• 2010

Using a speeded classification task (Garner, 1978), we investigated the perceptual interaction of distinctive features in Korean consonants. The main questions of this study were whether listeners can perceptually identify the component features that make up complex consonant sounds, whether these features are processed independently or dependently and whether there is a systematic hierarchy in their dependency. Participants were asked to classify syllables based on their difference in distinctive features in the task. Reaction times for this task were also gathered. For example, participants classified spoken syllables /ta/ and /pa/ as one category and /$t^ha$/ and /$p^ha$/ as another in terms of aspiration condition. In terms of articulation, participants classified /ta/ and /$t^ha$/ as one category and /pa/ and /$p^ha$/ as another. We assumed that the difference between their RTs represents their interdependency. We compared the laryngeal features and place features (Experiment 1), resonance features and place features (Experiment 2), and manner features and laryngeal features (Experiment 3). The results showed that distinctive features were not perceived in a completely independent way, but they had an asymmetric and hierarchical interdependency. The laryngeal features were found to be more independent compared to place and manner features. We discuss these results in the context of perceptual basis in phonology.

• Phonetics and Speech Sciences
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• v.2 no.2
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• pp.117-121
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• 2010

The This study aimed to evaluate the effects of the voice therapy we operated to the patients with age-related dysphonia. Thirty four participants who were diagnosed as age-related dysphonia in laryngoscopic finding from January, 2009 to December, 2009 completed the study. The participants were aged from 60 to 82 years old with a mean age of 70.6. All participants had received the abdominal breath technique, SKHPIP with laughter, and basic vocal training with description of their problem, the length of which ranged from four sessions to twelve sessions. We executed the videostroboscopy to compare the aspect of voicing change and the perceptual assessment, voice range profile, acoustic and aerodynamic measures to identify change of voice. Participants had glottal gap due to incomplete glottic closure during voicing on the pretest. After they took the voice therapy, the glottic gap became narrow and rough and breathy voice was reduced. There were significant difference in acoustic and aerodynamic measures. Jitter, Shimmer, MFR were reduced and MPT, Psub were increased(p<.05). Participants' pitch range and intensity range were increased on the posttest performance after taking voice therapy. Especially, most of them were showed that pitch range was increased significantly in high frequency area. The results of this investigation indicate that the voice therapy using abdominal breath, SKHPIP, and exercise together is effective for the patients who have age-related dysphonia to improve their voice quality. We recommend to apply this technique to functional voice disorders who are showed glottal gap.

• Phonetics and Speech Sciences
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• v.2 no.2
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• pp.109-115
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• 2010

In this paper, we investigate a signal typing on the basis of visual impression of distinctive spectrogram. Pathological voices are classified into signal type 1, 2, 3, or 4 to estimate perturbation parameters and to mark perceptual rating based on Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V). The results suggest that perturbation analysis can be applied to only type 1 and 2 signals and the perceptual ratings of overall grade increase with each signal type, overall. A good inter-rater reliability is showed among three raters. We recommend that pathological voices should be marked the signal typing and CAPE-V, together, to definitely describe the characteristics of pathological voices.

• Phonetics and Speech Sciences
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• v.2 no.2
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• pp.93-100
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• 2010

The purpose of this study was to investigate the differences of feeding ability and articulatory function in the children with spastic cerebral palsy and typically developing children according to feeding subtypes. The feeding subtypes were limited by chewing, cup drinking and spoon feeding. 14 children with spastic cerebral palsy and 14 typically developing children were participated in this study. The results were following as; First, there were significant differences in overall articulatory function between two groups Second, all scores of articulators' function according to feeding subtypes in children with cerebral palsy was significantly higher than typically developing children Third, chewing mode in feeding subtypes was highly correlated with lip and tongue movement. compared to another Finally, the correlation between spoon feeding and mobility of lip and tongue was high in both groups. These results suggested that These results suggest that the effort to find out the differences feeding ability and appliances for articulatory function in CP children are meaningful in catching their speech ability indirectly. Moreover, the more organized feeding skills should be discussed in the relationship with verbal and nonverbal development.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.51-58
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• 2010

English vowels play an important role in the daily communication between Korean students and international visitors. However, many Korean students still have difficulty producing them distinctively. Vowels vary according to shapes of oral and pharyngeal cavities, which are mainly determined by the degree of jaw opening and tongue position. Yang (2008a) proposed a simplified chart of English and Korean vowels for an educational purpose. He also suggested to use wooden chopsticks to secure distinguishable jaw openings. The purpose of this study is to tap whether wooden chopsticks can be applicable to a method for correcting English vowel pronunciation. Twelve male and female students participated in the recordings of eight /hVd/ words followed by additional recordings with wooden chopsticks between upper and lower teeth. The first and second formant trajectories of both natural and controlled vowel productions were obtained and compared at six equidistant measurement points using Praat. Results showed that the formant values of natural vowel productions were comparable to those of controlled productions. Vowels with similar formant trajectories of male students were separated with the aid of chopsticks. The width of each chopstick could be controlled similarly in the experiment. The author concludes that wooden chopsticks can be useful to correct vowel pronunciation. Further studies are desirable for native speakers to make perceptual evaluations of controlled vowel productions by nonnative speakers.

• Phonetics and Speech Sciences
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• v.2 no.2
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• pp.85-92
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• 2010

The purpose of this study was to know the differences in perceptual judgement for speech intelligibility in monosyllables by inexperienced listeners and vowel space area according to different dysarthric severity. Three dysarthric speakers with different severity(mild, moderate and severe) screened by 3 clinicians' screening tests before the experiment were conducted. Corner vowels (i, u, ae, a) in monosyllable level (CVC, 'p_p') and carrier phrases ('종이에_써') were chosen and analyzed for vowel space. Inexperience listeners (n=20) performed the intelligibility test for spoken syllables and carrier phrases by dysarthric speakers. The results show that there is a significant differences in both F1 and F2 values among 4 corner vowels. Vowel space area in the data of mildly impaired speakers was significantly higher than two others. In the scores of speech intelligibility judged by inexperienced listeners, the scores by a moderately impaired speaker were more higher than two other speakers. The discrepancy between perceptual judgement by inexperienced listeners and vowel space area will be discussed in this area.