• Speech Sciences
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• v.11 no.4
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• pp.223-232
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• 2004

This study investigated and compared the acoustic characteristics of the Korean stop sound [k'] in three different phonological environments: the tensified lenis stop [k'] as observed in /prek+kaci/, the fortis stop /k'/ as in /pre+k'aci/, and the fortis stop /k'/ following an obstruent as in /prek+k'aci/. The specific research question was whether or not the tensified lenis stop shares all the acoustic features with the other two kinds of fortis stops. The acoustic measures adopted in this study were H1*-H2*, VOT, length of stop closure, and $F_0$. The major findings were that the three stops showed no significant difference in all the acoustic measures except the length of stop closure. The fortis stop /k'/ following an obstruent showed significantly longer duration of stop closure than the other two stops, both of which showed no significant difference. Based on these phonetic results, this study argued that, for the proper phonological description of post-obstruent tensification, the phonological feature [slack vocal folds] of a lenis stop should be changed into [stiff vocal folds, constricted glottis] that the fortis stops should have.

• MALSORI
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• no.57
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• pp.15-30
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• 2006

This paper investigates differences between generations in the vowel system of the Daegu dialect in terms of F1 and F2 of the monophthongs. Three different groups of subjects participated in the present study: 20 female native speakers of the Daegu dialect(10 in their 20's and 10 in their 40's), and 10 female native speakers of the Seoul dialect as a control group. It has been assumed that the Daegu dialect has six vowels. However, younger generation appears to have 7 vowels different from older generation. The result of the present study showed that the Daegu dialect has different vowel systems between generations: for 40's have six vowels and 20's have seven vowels. These differences seems to be attributed to the influence of the Seoul dialect.

• Clinical and Experimental Pediatrics
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• v.53 no.4
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• pp.579-584
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• 2010

Purpose : The number of the repatriated Korean students who had overseas study at early ages is increasing. They received foreign education, they can speak international languages, but they have many difficulties in articulation and intonation of the Korean language. This study aims to measure closure and aspiration duration, length of consonants, length of subsequent vowels, and ratio of consonants against subsequent vowels in vowel-consonant-vowel (VCV) syllables. Methods : This study compares the acoustic and phonetic characteristics of repatriated and native students, the ratio of articulation error of Korean plosives, the closure and aspiration duration, and the ratio of the aspiration duration against the closure duration. Results : The ratio of articulation error of Korean plosives between repatriated and native students is 19% and 2%, respectively. The closure duration was significantly longer in repatriated students than in native students. The aspiration duration was significantly longer in repatriated students than in native students. No difference was found in the ratio of aspiration duration against closure duration between the native and repatriated students. Conclusion : This study can be a good reference for estimating the phonetic difficulties of Korean elementary students who had overseas study at early ages.

• Phonetics and Speech Sciences
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• v.6 no.2
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• pp.73-79
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• 2014

Alveolar fricative sounds /s/ and /s'/ are learned last for normal children in the speech development process for Koreans. These are especially difficult to articulate for hearing-impaired children often causing articulation errors. The acoustic phonetic evaluation uses testing tools to provide indirect and object information. These objective resources can be compared with standardized resources on speech when interpreting the results of a test. However, most previous studies in Korea did not consider acoustic studies that used the spectrum moment values of hearing-impaired children. Therefore, this study was conducted to compare the characteristics of hearing-impaired children's pronunciation of fricative sounds using spectrum moment values. For this purpose, the study selected a total of 10 hearing-impaired children (5 boys and 5 girls) currently in 3rd or 5th grade and attending one of the elementary schools in Seoul or Gyeonggi-do. For the selection process, their age, type of hearing aid, implantation of hearing aid (CI) before two years of age, hearing capacity (dB) before and after wearing the hearing aid, duration of speech rehabilitation, and time of learning alveolar fricative sounds were all considered. Also, 10 normal children (5 boys and 5 girls) were selected among 3rd or 5th grade students attending one of the elementary schools in Seoul or Gyeonggi-do. The subjects were asked to read the carrier sentence, "I say _______," including a list of 12 meaningless syllables composed of CV and VCV syllables, including alveolar fricative sounds /s/ and /s'/ and vowels /a/, /i/, and /u/. The recorded resources were processed through the Time-frequency Analysis Software Program to measure M1 (mean), M2 (variance), M3 (skewness), and M4 (kurtosis) of the fricative noise. No significant differences were found when comparing spectrum threshold values in the acoustic phonetic characteristics of hearing-impaired children and normal children in alveolar fricative sound pronunciation according to vowels /a/, /i/, and /u/, alveolar fricative sounds /s/ and /s'/, and syllable structure (CV, VCV) other than, for M3 in the comparison of groups according to disability. In the comparison of syllable structures, there were statistically significant differences in M1, M2, M3, and M4 with clinical significance. However, there was no significant difference in results when comparing the alveolar fricative sounds according to the vowels.

• MALSORI
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• no.47
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• pp.73-84
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• 2003

This study investigates differences in intensity across the three different Korean obstruent types in terms of the RMS amplitude of both the entire section and the first 512 samples of the immediately following vowel in two positions. The results showed that for the utterance initial position the RMS amplitude of both the entire section and the first 512 samples of the vowel was greatest for fortis obstruents, intermediate for aspirated ones, and weakest for lenis ones, with a significant difference between each pair of them. For the intervocalic position, in contrast, the intensity of the entire vowel was greatest for fortis obstruents, intermediate for lenis ones, and weakest for aspirated ones, with no significant difference between the last two groups, whereas the intensity of the first 512 samples of the vowel was greatest for fortis obstruents, intermediate for lenis ones, and weakest for aspirated ones, with a significant difference between each pair of the three groups. This means that the intensity of the earlier part of the vowel functions as a discriminator of Korean obstruents. The positional difference is due to the different behavior of the lenis obstruents in the intervocalic position, such that the intensity build-up is already on its way with voice lead.

• MALSORI
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• no.58
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• pp.1-18
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• 2006

The purpose of this study was to investigate diadochokinetic (DDK) characteristics in the subjects with spastic cerebral palsy (CP) by severity. DDK characteristics were measured through rate, regularity, accuracy and consistency in Alternate Motion rate (AMR) and Sequential Motion rate (SMR) tasks. The subjects participated in this study included 27 subjects with spastic CP (mild- 9, moderate- 9, severe- 9) and 9 normal persons who are around 11-20 years old. On the result of this study, rate in AMR was significant difference between all spastic groups and normal group, and rate in SMR was significant difference between normal and mild groups and moderate and severe groups. In regularity of the DDK tasks, severe group had significant difference the other groups. Finally, accuracy and consistency of the DDK tasks exhibited significant difference between all spastic groups and normal group. In conclusion, the subjects with spastic CP have a tendency to produce slow and irregular syllable repetition as severity increases, but to produce inaccurate and inconsistent syllable repetition regardless of severity in the DDK tasks.

• The Journal of the Acoustical Society of Korea
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• v.19 no.6
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• pp.28-33
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• 2000

This paper investigates the durational difference between syllable final segment and syllable initial one within word level. The Korean consonant (m) and (nn) were focused mainly. It could hardly say that there was significant difference between preceding consonant and following one, but it was observed that the preceding consonant tended to be shorter than the following one in the (mm) case. This might be explained by the fact that bilabial sound should appear at the first step of language acquisition. This leads to the conclusion that the articulation of preceding (m) shall be easier than others. In the case of alveolar geminate (nn), there was considerable statistic difference between preceding and following segments. It tends to be that the preceding consonant has longer duration.

• Proceedings of the KSPS conference
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• 2000.07a
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• pp.332-332
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• 2000

The purpose of this study is to investigate the perception and production of English vowels by native speakers of Korean. In perception test, twelve English vowels /${\ae},{\;}a,{\;}{\Game},{\;}e,{\;}{\varepsilon},{\;}i,{\;}I,{\;}a,{\;}o,{\;}u,{\wedge},{\;}{\mho}$/, as in had, hard, hoard, hayed, head, heed, hid, hod, hoed, whod, Hudd, and hood produced by native speakers of English were used as perception test materials and subjects were asked to identify the vowels. Two different groups of subjects participated in the perception test. One consisted of 90 students who were taking an English phonetics course, and the other consisted of 64 who were not. The results showed that the former did better than the latter m identifYing English vowels, and that vowels in 'head' and 'had' were relatively hard to identify, while vowels in 'hayed', 'hard', and unexpectedly, 'heed' and hid' were easy to perceive. In production test, two native English speakers and 4 native Korean speakers served as subjects. The 4 native Korean speakers were divided into two groups as in the perception test, experienced and inexperienced, depending on whether they were taking an English phonetics course or not. Native English speakers generally showed significant differences both in vowel duration and in FI & F2 values between members of the vowel pairs which are of special interest of this study: /i/ vs. /I/, /${\ae}$/ vs. /$\varepsilon$/, and /u/ vs. and /$\mho$/. There was no significant difference between the two Korean groups. Native Korean speakers showed much difference in neither duration nor FI & F2 values except significant durational difference in /i/ vs. /I/ pair.

• Proceedings of the KSPS conference
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• 2006.11a
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• pp.127-130
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• 2006

The purpose of this study is to examine the difference in acoustic features between Young Voices and Aged Voices, which are actually come from the same age group. The 12 female subjects in their thirties were participated and recorded their sustained vowel /a/, connected speech, and reading. Their voices were divided into Younger Voices and Aged Voices, which means voices sound like younger person and sound like in their age or more aged ones. Praat 4.4.22 was used to record and analyze their acoustic features like Fo, SFF, Jitter, Shimmer, HNR, Pitch-range. And the six female listeners guessed the subjects' age and judged whether they sound younger or as like their actual age. We used the Independent t-Test to find the significant difference between those two groups' acoustic features. The result shows a significant difference in Fo, SFF. The above and the previous studies tell us the group who sounds like younger or baby like voice has the similar acoustic features of actually young people.

• MALSORI
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• no.35_36
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• pp.1-12
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• 1998

This study aims to investigate the prosodic characteristics of Korean discourse sentences, especially focusing the initial and final part of a sentence. 50 disourse sentences were read in two different styles; one, sentence by sentence, the other, continuous of all 50's. First, we tried to get two kinds of ratios from the acoustic results: first, ratio of the final syllable to the initial syllable in first word in a sentence; second, ratio of the final syllable to the initial syllable in last word in a sentence. We, then, calculated statistical values of the ratios including mean, standard deviation, minimum, maximum, and p-values in t-test. With respect to duration, there were little difference between two different styles. If any, we could see tiny unharmonious durational aspect in the initial of continuous reading. More concisely, there could be observed some deviation from standard. In case of F0, there was prominent statistical difference between ratios of last words in two styles. This difference might play a role as a prosodic feature. Energy seems to show similar pattern with that of F0. The results showed that final syllable in last word was pronounced with about 85 % of initial syllable in the same context and the last words in continuous speech were strongly articulated compared with those of sentence by sentence reading.