• Speech Sciences
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• v.9 no.2
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• pp.25-47
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• 2002

Human language activity in the information society has been developing the communication system between humans and machines. The aim of this study was to analyze dialectal speech in Korea. One hundred Kyungsang and one hundred Cholla informants participated in this study. A CSL and Flexible laryngeal fiberscope were used for analysis of the acoustic and glottal gestures of all the vowels and consonants. Test words were made on the picture cards and letter cards which contained each vowel and each consonant, respectively. The dialogue between the examiner and the informants was recorded in a question and answer manner. The acoustic results of two dialects were as follows: Kyungsang and Cholla informants showed neutralization between /e/ and /$\varepsilon$. However, the apertures of Kyungsang vowels /i, w, u, o/ were higher than those of Cholla vowels. The /wi/ and /$\varepsilon$/ of Kyungsang Diphthong vowels were shown as simple vowels /i/ and /$\varepsilon$/ in Cholla dialect. The VOT of Cholla dilaect was longer than that of Kyungsang dialect. The fricative frequence of Kyurlgsang dialect was about 1000Hz higher than that of Cholla dialect. The glottal widths on fiberscopic images showed that the consonant durations of Kyungsang and Cholla dialects were correlated all together with the acoustic duration on the spectrogram.

• Speech Sciences
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• v.10 no.1
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• pp.95-105
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• 2003

This paper describes a new parameter for voice activity detection which serves as a front-end part for automatic speech recognition systems. The new parameter called run-ratio is derived from the runs test statistic which is used in the statistical test for randomness of a given sequence. The run-ratio parameter has the property that the values of the parameter for the random sequence are about 1. To apply the run-ratio parameter into the voice activity detection method, it is assumed that the samples of an inputted audio signal should be converted to binary sequences of positive and negative values. Then, the silence region in the audio signal can be regarded as random sequences so that their values of the run-ratio would be about 1. The run-ratio for the voiced region has far lower values than 1 and for fricative sounds higher values than 1. Therefore, the parameter can discriminate speech signals from the background sounds by using the newly derived run-ratio parameter. The proposed voice activity detector outperformed the conventional energy-based detector in the sense of error mean and variance, small deviation from true speech boundaries, and low chance of missing real utterances

• Phonetics and Speech Sciences
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• v.7 no.3
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• pp.107-115
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• 2015

In this paper English word-final /s/ and /z/ produced by English and Korean speakers were investigated. The durations and maximum intensities of these fricatives with those of their preceding vowels were compared. In the English speakers' productions, they relied on the ratio of the durations of them as well as the ratio of the maximum intensities of them. In their productions, the /s/ was long in duration and high in maximum intensity and its preceding vowel was short in duration whereas the /z/ was short in duration and low in maximum intensity and its preceding vowel was long in duration. However, the maximum intensities of the preceding vowels were not different in their productions. But in the Korean speakers' productions, they relied on neither the ratio of the durations of them nor the ratio of the maximum intensities of them. In their productions, the /s/ and the /z/ were not different in durations, but the duration of the preceding vowel of the /s/ was shorter than that of /z/, and the maximum intensities of the /s/ and /z/ as well as their preceding vowels were not different. Based on these results we can conclude that in distinguishing /CVs/ and /CVz/ words, English speakers used durations and intensities of the word-final fricatives in addition to durations of the vowels whereas Koreans used only durations of the vowels.

• Phonetics and Speech Sciences
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• v.7 no.3
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• pp.165-173
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• 2015

This study was aim to compare the phonological error patterns and PCC(Percentage of Correct Consonants) derived from the single word and spontaneous speech contexts of the speech sound disorders with unknown origin(SSD). The present study suggest that the development phonological error patterns and non-developmental error patterns of the target children, in according to speech context. The subjects were 15 children with SSD up to the age of 5 from 3 years of age. This research use 37 words of APAC(Assessment of Phonology & Articulation for Children) in the single word context and 100 eojeol in the spontaneous speech context. There was no difference of PCC between the single word and the spontaneous speech contexts. Significantly different developmental phonological error patterns between the single word and the spontaneous speech contexts were syllable deletion, word-medial onset deletion, liquid deletion, gliding, affrication, fricative other error, tensing, regressive assimilation. Significantly different non-developmental phonological error patterns were backing, addtion of phoneme, aspirating. The study showed that there was no difference of PCC between elicited single word and spontaneous conversational context. And there were some different phonological error patterns derived from the two contexts of the speech sound disorders. The more important interventions target is the error patterns of the spontaneous speech contexts for the immediate generalization and rising overall intelligibility.

• Phonetics and Speech Sciences
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• v.11 no.3
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• pp.23-29
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• 2019

This study acoustically examines the quality of fricatives produced by ten dysarthric speakers with cerebral palsy. Previous similar studies tend to focus only on sibilants, but to obtain a better understanding of how dysarthria affects fricatives we selected a range of samples with different places of articulation and voicing. The Universal Access (UA) Speech database was used to select thirteen words beginning with one of the English fricatives (/f/, /v/, /s/, /z/, /ʃ/, /ð/). The following four measurements were taken for both dysarthric and healthy speakers: phoneme duration, mean spectral peak, variance and skewness. Results show that even speakers with mild dysarthria have significantly longer fricatives and a lower mean spectral peak than healthy speakers. Furthermore, mean spectral peak and variance showed significant group effects for both healthy and dysarthric speakers. Mean spectral peak and variance was also useful for discriminating several places of articulation for both groups. Lastly, spectral measurements displayed important group differences when taking severity into account. These findings show that in general there is a degradation in the production of fricatives for dysarthric speakers, but difference will depend on the severity of dysarthria along with the type of measurement taken.

• The Journal of Korean Academy of Prosthodontics
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• v.8 no.1
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• pp.56-64
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• 1968

저자(著者)는 구개도(口蓋圖)에 의(依)하여 한국어(韓國語) 마찰음(摩擦音)의 라, 사, 자, 차 사행(四行), 도합(都合) 40음(音)에 대(對)한 정당교합자(正堂咬合者) 오인(五人)과 부정교합자(不正咬合者) 십칠인(十七人)의 발음(發音)을 조사(調査)하여 다음과 같은 결과(結果)를 얻었다. 1) 라, 사, 자, 차 사행(四行)의 구개도(口蓋圖)는 V, H 및 C형(型)을 나타낸다. 2) 라행(行)의 구개도(口蓋圖)는 교합군(咬合群)에 관계(關係)없이 주(主)로 H형(型)을 보인다. 라행(行)에 있어서 전치(前齒)와 접촉부위간(接觸部位間)의 거리는 과개교합군(過蓋咬合群)에서 크고, 반대교하군(反對咬合群)에서는 작다. 3) 사행(行)은 주(主)로 V형(型)을 보이며 반대교합군(反對咬合群)에서만 C형(型)이 1/3정도(程度) 나타난다. 반대교합군(反對咬合群)에서의 V형(型)은 그 접촉부위(接觸部位)가 구치부(臼齒部)로 갈수록 두터워 진다. 4) 자, 차행(行)의 구개도(口蓋圖)는 라, 사행(行)에 비(比)하여 변화(變化)가 많다. a) 과개교합군(過蓋咬合群)은 H형(型)이 67%이고 나머지는 C형(型). b) 반대교합군(反對咬合群)은 거의 모두가 C형(型). c) 과개교합군(寡蓋咬合群)에서는 반이상(半以上)이 C형(型), 나머지는 H형(型)이나 간혹 V형(型)도 출현(出現)한다. 5) 구치부(臼齒部)에서의 측방반대교합(側方反對咬合)의 경우는 반대교합(反對咬合)이 있는 반대(反對)쪽의 접촉부위(接觸部位)가 넓다. 6) 과개교합군(寡蓋咬合群)에서의 접촉부위(接觸部位)는 정상군(正常群)이나 과개교합군(過蓋咬合群)에서 보다 일반적(一般的)으로 넓게 나타난다.

• The Journal of the Korea Contents Association
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• v.9 no.1
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• pp.455-464
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• 2009

Based on the observation that Korean speakers of English have difficulties in producing English fricatives, a perception experiment was designed to investigate whether Korean speakers also have difficulties perceiving English labial consonants including fricatives. Forty Korean college students were asked to perform a multiple-choice identification test. The consonant perception test consisted of nonce words which contained English labial consonants [p, b, f, v] in 4 different prosodic locations: initial onset position, intervocalic position before stress, intervocalic position after stress, and final coda position. The general perception pattern was that the mean accuracy rates were higher in strong position like CV and VCVV than in weak position like VC and VVCV. The difficulties in perceiving the English targets resulted mainly from bidirectional manner confusion between stop and fricative across all prosodic locations. The other types of misidentification were due to place confusion as well as voicing confusion. Place confusion was generated mostly by the target [f] in all prosodic position due to acoustic properties. Voicing confusion was heavily influenced by prosodic position. The misperception of the participants was accounted for by phonetic properties and/or the participants' native language properties.

• Proceedings of the KSPS conference
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• 2007.05a
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• pp.211-212
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• 2007

Stroke makes several physical deficits. Dysarthria is one of the most difficult problems in conventional medicine because of the weakness of neuromotor control. The purpose of this study is to find the acoustic characteristics of acupuncture therapy effects on post-stroke dysarthria. Seven patients with stroke(infarction or hemorrhage) were selected by CT or MR imaging. The authors applied acupuncture therapy by inserting needles into 8 acupuncture points, ipsilateral ST4, ST6 and contralateral LI4, ST36 on facial palsy side, and CV23, CV24, bilateral "Sheyu" for 4 weeks. Speech sample were composed of five simple vowels /a,e,i,o,u/ and meaningless polysyllabic words CVCVC(C: stops, affricated, fricative sounds, v: /e/). .VOT, total duration of each speech samples and vowel formant (F1&F2) were analyzed on Spectrogram. The results are as follows: 1. VOT of bilabial and velar stops was decreased post treatment. The VOT of bilabial glottalized pre and post treatment were statistically significant (p < 0.05). 2. Total duration of polysyllabic words was decreased post treatment. Decrement of total duration containing the bilabial was statistically significant (p<0.05). 3. First formant of round vowel /o/ pre and post treatment was statistically significant (p<0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.2
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• pp.375-388
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• 1996

It has widely known for speech problem in patients with malocclusion, but there have been insufficient studies on degrees of severity. Patients with openbite and Cl III malocclusion usually have speech problem. It has widely known that fricative /s/is pronunciated most abnormally in Cl III malocclusion than any other consonant. Therefore 20 children with anterior crossbite were selected for study groups and 40 children with normal anterior occlusion were selected for control group. 7 sounds such as / 사(sa), 서($s{\delta}$), 소(so), 수(su), 스($s{\omega}$), 시(si), 세(se) / were recorded, and the formants and formants ratios were measured by using Sensimetric Speech Station, which is speech analyzing program in IBM PC. The results were as follows : 1. In anterior crossbite group, F1 of all 7 sounds were significantly higher than normal anterior relationship group(p<0.05). 2. There were no significant difference in F2 between two groups except / 소(so), 수(su)/(p>0.05). 3. In anterior crossbite group, F2/F1 ratio of all 7 sounds were significantly smaller than normal anterior relationship group(p<0.05). 4. There were no significant difference in accordance with tongue position(p>0.05).

• Phonetics and Speech Sciences
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• v.7 no.3
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• pp.139-149
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• 2015

This paper aims to analyze pronunciation variations of loanwords produced by Korean and improve the performance of pronunciation modeling of loanwords in Korean by using syllable-based segmentation and phonological knowledge. The loanword text corpus used for our experiment consists of 14.5k words extracted from the frequently used words in set-top box, music, and point-of-interest (POI) domains. At first, pronunciations of loanwords in Korean are obtained by manual transcriptions, which are used as target pronunciations. The target pronunciations are compared with the standard pronunciation using confusion matrices for analysis of pronunciation variation patterns of loanwords. Based on the confusion matrices, three salient pronunciation variations of loanwords are identified such as tensification of fricative [s] and derounding of rounded vowel [ɥi] and [$w{\varepsilon}$]. In addition, a syllable-based segmentation method considering phonological knowledge is proposed for loanword pronunciation modeling. Performance of the baseline and the proposed method is measured using phone error rate (PER)/word error rate (WER) and F-score at various context spans. Experimental results show that the proposed method outperforms the baseline. We also observe that performance degrades when training and test sets come from different domains, which implies that loanword pronunciations are influenced by data domains. It is noteworthy that pronunciation modeling for loanwords is enhanced by reflecting phonological knowledge. The loanword pronunciation modeling in Korean proposed in this paper can be used for automatic speech recognition of application interface such as navigation systems and set-top boxes and for computer-assisted pronunciation training for Korean learners of English.