• Proceedings of the KSPS conference
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• 1996.02a
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• pp.9-22
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• 1996

Among the various dysarthric subtypes, diagnosis of ataxic dysarthria is rendered when the speech characteristics include imprecise and irregular articulatory breakdowns, marked degree of speech rate impairment, overall monopitch and monoloudness, and respiratory-articulatory incoordination. Traditionally, speech pathologists have relied only upon their ‘ears’ to describe and evaluate the dysarthric speech. A statement of percentage of correct words identified by a listener do not provide so much more than an index of severity. Within the same perceptual dimension, a carefully constructed speech intelligibility test can specify patterns of errors. The patterns can contain a diagnostic value as well as Provide strategies for remediation. The phonetically transcribed texts on single words and a standard passage, 'kail' produced by an ataxic dysarthria are presented in this report, with an emphasis of the articulatory error analysis. Furthermore,, acoustic tools [e.g., spectrography to measure formant transitions, segment durations, consonant spectra, etc.] are utilized to serve as basic measures that objectively document patients' speech intelligibility, Finally, the treatment methods [e.g., spectrography as a visual feedback, gestural reorganization using pacing method, DAF (Delayed Auditory Feedback)] to modify the dysarthric behaviors are presented.

• 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.

• MALSORI
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• no.21_24
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• pp.111-122
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• 1992

본 논문에서는 한국어에 있어서 세 가지 유형의 파열음과 일본어에 있어서 두 가지 유형의 파열음과 일본어에 있어서 두 가지 유형의 파열음이 보여주는 시간적 특성을 어두 위치 및 모음간 위치로 나누어 비교해 보았다- 한국어에 있어서 세 가지 유형의 파열음은 어두 위치에서 모두 무성음으로 실현되므로 성의 대립으로는 이들을 유형화 할 수 없고, 그보다는 조음의 힘과 기식의 유무에 따라 연음, 무기 경음, 유기 경음으로 분류하는 것이 타당하다. 이에 비해 일본어 파열음은 유성음인 연음과 무성음인 경음의 두가지 유형으로 대립된다. 유성음과 무성음, 그리고 유기음과 무기음의 구분에는 파열음의 개방에서부터 성대 진동까지의 시간인 성 시작 시간(VOT)과 기식의 길이가 변수가 된다. 경음과 연음의 구분에는 선행 모음의 길이, 폐쇄 지속 시간, Vl/(Vl+CL)의 비율이 유용한 정보가 된다. 양국어 어두 파열음의 VOT를 비교해 볼 때, 일본어 유성음은 음수의 VOT를 가지며, 한국어 무기 경음에서는 VOT가 10msec정도로 짧게 나타나고, 그 다음으로 한국어 연음. 일본어 무성음, 한국어 유기 경음의 순서로 길어진다. $\frac{선행 모음의 길이}{(선행 모음의 길이+폐쇄 지속 시간)}$의 비율은 언어의 특성도 반영해 주는데, 한국어의 경우 연음: 무기 경음: 유기 경음의 비는 0.63: 0.30:0.35, 일본어의 경우 유성음:무성음의 비는 0.69: 0.45로 나타났다. 청취 실험을 통해 한국인의 자음 인식 경향을 살펴본 결과, 성대 진동의 유무를 변별적으로 사용하지 않는 한국인 화자는 일본어 유성음은 연음으로, 무성음은 경음으로 인식하는 경향이 있는 것으로 나타났다.

• Proceedings of the IEEK Conference
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• summer
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• pp.391-394
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• 2004

This paper focuses on the DSP implementation of an HMM-based speech recognizer that can handle several hundred words of vocabulary size as well as speaker independency. First, we develop an HMM-based speech recognition system on the PC that operates on the frame basis with parallel processing of feature extraction and Viterbi decoding to make the processing delay as small as possible. Many techniques such as linear discriminant analysis, state-based Gaussian selection, and phonetic tied mixture model are employed for reduction of computational burden and memory size. The system is then properly optimized and compiled on the TMS320C6711 DSP for real-time operation. The implemented system uses 486kbytes of memory for data and acoustic models, and 24.5kbytes for program code. Maximum required time of 29.2ms for processing a frame of 32ms of speech validates real-time operation of the implemented system.

• MALSORI
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• no.60
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• pp.67-84
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• 2006

The purpose of this study is to find some acoustic parameters on frequency domain to distinguish the Korean nasals, $/m,\;n,\;{\eta}/$ from each other. The new parameters are devised on the basis of LTAS (Long Term Average Spectrum). The maximum peak amplitude and the relevant formant frequency are measured in low and high frequency range, respectively. The frequency of spectral valley and its energy level are also obtained in the specific frequency range of the spectrum. Spectral slope, total energy value in specific frequency range, statistical distribution of spectral energy like centroid, skewness, and kurtosis are suggested as new parameters as well. The parameters that show statistically significant differences across nasals are summerized as follows. 1) in syllable initial positions: the total energy value from 1,500 to 2,200 Hz(zeroENG); 2) in syllable final positions: the peak amplitude of the first formant(peak1_a), the formant frequency with maximum peak amplitude from 4,000 to 8,000 Hz(peak2_f), the maximum peak amplitude of the formant frequency from 4,000 to 8,000 Hz(peak2_a), and the total energy value from 1,500 to 2,200 Hz(zeroENG).

• Cross-Cultural Studies
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• v.28
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• pp.115-139
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• 2012

Interval or duration of segments, syllables, words and phrases is an important acoustic feature which influences the naturalness of speech. A number of cross-sectional studies regarding acoustic characteristics of children's speech development found that intervals of segments, syllables, words and phrases tend to change with the growing age. One hypothesis assumed that decreases in intervals would be greater when children were younger and smaller decreases in intervals when older (Thelen,1991), it has been supported by quite a number of researches on the basis of cross-sectional studies (Tingley & Allen,1975; Kent & Forner,1980; Chermak & Schneiderman, 1986), but the other hypothesis predicted that decreases in intervals would be smaller when children were younger and greater decreases in intervals when older (Smith, Kenney & Hussain, 1996). Researchers seem to come up with conflicting postulations and inconsistent results about the change trends concerning intervals of segments, syllables, words and phrases, leaving it as an issue unresolved. Most acoustic investigations of children's speech production have been conducted via cross-sectional designs, which involves studying several groups of children. So far, there are only a few longitudinal studies. This issue needs more longitudinal investigations; moreover, the acoustic measures of the intervals of child speech are hardly available. All former studies focus on word stages excluding the babbling stages especially the canonical babbling stage, but we need to find out when concrete changes of intervals begin to occur and what causes the changes. Therefore, we conducted an acoustic study of interval characteristics of segments and words concerning Canonical Babble ( CB) and early speech in an infant aged from 0;9 to 2;4 acquiring Mandarin Chinese. The current research addresses the following two questions: 1. Whether decreases in interval would be greater when children were younger and smaller when they were older or vice versa? 2. Whether the child speech concerning the acoustic features of interval drifts in the direction of the language they are exposed to? The female infant whose L1 was Southern Mandarin living in Changsha was audio- and video-taped at her home for about one hour almost on a weekly basis during her age range from 0;9 to 2;4 under natural observation by us investigators. The recordings were digitized. Parts of the digitized material were labeled. All the repetitions were excluded. The utterances were extracted from 44 sessions ranging from 30 minutes to one hour. The utterances were divided into segments as well as syllable-sized units. Age stages are 0;9-1;0,1;1-1;5, 1;6-2;0, 2;1-2;4. The subject was a monolingual normal child from parents with a good education. The infant was audio-and video-taped in her home almost every week. The data were digitized, segments and syllables from 44 sessions spanning the transition from babble to speech were transcribed in narrow IPA and coded for analysis. Babble was coded from age 0;9-1;0, and words were coded from 1;0 to 2;4, the data has been checked by two professionally trained persons who majored in phonetics. The present investigation is a longitudinal analysis of some temporal characteristics of the child speech during the age periods of 0;9-1;0, 1;1-1;5, 1;6-2;0, 2;1-2;4. The answer to Research Question 1 is that our results are in agreement with neither of the hypotheses. One hypothesis assumed that decreases in intervals would be greater when children were younger and smaller decreases in intervals when older (Thelen,1991); but the other hypothesis predicted that decreases in intervals would be smaller when children were younger and greater decreases in intervals when older (Smith, Kenney & Hussain, 1996). On the whole, there is a tendency of decrease in segmental and syllabic duration with the growing age, but the changes are not drastic and abrupt. For example, /a/ after /k/ in Table 1 has greater decrease during 1;1-1;5, while /a/ after /p/, /t/ and /w/ has greater decrease during 2;1-2;4. /ka/ has greater decrease during 1;1-1;5, while /ta/ and /na/ has greater decrease during 2;1-2;4.Across the age periods, interval change experiences lots of fluctuation all the time. The answer to Research Question 2 is yes. Babbling stage is a period in which the children's acoustic features of intervals of segments, syllables, words and phrases is shifted in the direction of the language to be learned, babbling and children's speech emergence is greatly influenced by ambient language. The phonetic changes in terms of duration would go on until as late as 10-12 years of age before reaching adult-like levels. Definitely, with the increase of exposure to ambient language, the variation would be less and less until they attain the adult-like competence. Via the analysis of the SPSS 15.0, the decrease of segmental and syllabic intervals across the four age periods proves to be of no significant difference (p>0.05). It means that the change of segmental and syllabic intervals is continuous. It reveals that the process of child speech development is gradual and cumulative.

• Phonetics and Speech Sciences
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• v.2 no.2
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• pp.3-16
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• 2010

This study aims at setting the hierarchy of difficulty of the 7 Korean monophthongs for Mongolian learners of Korean according to Prator's theory based on the Contrastive Analysis Hypothesis. In addition to that, it will be shown that the difficulties and errors for Mongolian learners of Korean as a second or foreign language proceed directly from this hierarchy of difficulty. This study began by looking at the speeches of 60 Mongolians for Mongolian monophthongs; data were investigated and analyzed into formant frequencies F1 and F2 of each vowel. Then, the 7 Korean monophthongs were compared with the resultant Mongolian formant values and are assigned to 3 levels, 'same', 'similar' or 'different sound'. The findings in assessing the differences of the 8 nearest equivalents of Korean and Mongolian vowels are as follows: First, Korean /a/ and /$\wedge$/ turned out as a 'same sound' with their counterparts, Mongolian /a/ and /ɔ/. Second, Korean /i/, /e/, /o/, /u/ turned out as a 'similar sound' with each their Mongolian counterparts /i/, /e/, /o/, /u/. Third, Korean /ɨ/ which is nearest to Mongolian /i/ in terms of phonetic features seriously differs from it and is thus assigned to 'different sound'. And lastly, Mongolian /$\mho$/ turned out as a 'different sound' with its nearest counterpart, Korean /u/. Based on these findings the hierarchy of difficulty was constructed. Firstly, 4 Korean monophthongs /a/, /$\wedge$/, /i/, /e/ would be Level 0(Transfer); they would be transferred positively from their Mongolian counterparts when Mongolians learn Korean. Secondly, Korean /o/, /u/ would be Level 5(Split); they would require the Mongolian learner to make a new distinction and cause interference in learning the Korean language because Mongolian /o/, /u/ each have 2 similar counterpart sounds; Korean /o, u/, /u, o/. Thirdly, Korean /ɨ/ which is not in the Mongolian vowel system will be Level 4(Overdifferentiation); the new vowel /ɨ/ which bears little similarity to Mongolian /i/, must be learned entirely anew and will cause much difficulty for Mongolian learners in speaking and writing Korean. And lastly, Mongolian /$\mho$/ will be Level 2(Underdifferentiation); it is absent in the Korean language and doesn‘t cause interference in learning Korean as long as Mongolian learners avoid using it.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.20 no.1
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• pp.57-62
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• 2009

Background and Objectives : There are few studies reported that specifically examine the laryngeal function in patients with profound hearing loss or deafness, This study was designed to examine videostroboscopic findings and phonetic characteristics in adult patients with prelingually deaf. Materials and Method: Sixteen patients (seven males, nine females) diagnosed as prelingually deaf aged from 19 to 54 years, and were compared with a 20 normal control group with no laryngeal pathology and normal hearing group, Videostroboscopic evaluations were rated by experienced judges on various parameters describing the structure and function of the laryngeal mechanism during comfortable pitch and loudness phonations. Acoustic analysis test were done, and a nasalance test performed to measure rabbit, baby, and mother passage. CSL were measured to determine the first and two formant frequencies of vowels /a/, /i/, /u/, Statistical analysis was done using Mann-Whitney U or Wilcoxon signed ranks test. Results: Videostroboscopic findings showed phase symmetry but significantly more occurrences decrement in the amplitude of vibration, mucosal wave, irregularity of the vibration and increased glottal gap size during the closed phase of phonation, In addition, group of prelingually deaf patients were observed to have significantly more occurrences of abnormal supraglottic activities during phonation. The percentage of shimmer in the group of prelingually deaf patients were higher than in the control group. Characteristics of vowels were lower of the second formant of the vowel /i/. Nasalance in prelingually deaf patients showed normal nasality for all passages, Conclusion: Prelingually deaf patients show stroboscopic abnormal findings without any mucosal lesion, suggesting that they have considerable functional voice disorder. We suggest that prelingually deaf adults should perform vocal training for normalized laryngeal function after cochlear implantation.

• Journal of Sasang Constitutional Medicine
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• v.19 no.3
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• pp.75-88
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• 2007

1. Objectives The purpose of this study was to objectively diagnose American male and female's production of two vowels /a, i/ by Sasang Constitution. 2. Methods It was analyzed the constitutional characteristics of the American adults voices with PSSC-2004. of 134 cases of vowels /a, i/ with a duration of $2.5{\sim}3$ seconds were inputted in PSSC-2004 and analyzed into 40 factors. 3. Results and Conclusions 1) APQ In the male group's production of vowel /a/, the Soyangin's APQ(l), APQ(3) and APQ(4) were significantly high compared with those of Taeumin and Soeumin. 2) Shimmer In the male group's production of vowel /a/, Soeumin's Octave1 Shimmer was significantly low compared with that of Taeumin and Soeumin. In the male group's production of vowel /i/, Soeumin's D-Shimmer was significantly low compared with that of Taeumin and Soeumin. In the female group's production of vowel /a/, the Soyangin's C-Shimmer was significantly high compared with that of Taeumin and Soeumin. 3) Octave In the male group's production of vowel /a/, the Soyangin's Octave3, Octave4, Octave5, Octave6 and Octave1 Ratio were significantly high compared with those of Taeumin and Soeumin. In the male group's production of vowels /a, i/, the Soyangin's Octave4 was significantly high compared with that of Taeumin and Soeumin. 4) Energy In the male group's production of vowel /a/, the Soyangin's Time Domain Total Sum /Time Domain Count, Freq Domain Total Sum /cnt(0), 0k-4k Total Sum, Dev., A(A#, C, E, D#, E, F#) tot E, and A(C,, D#, F#) Dev. were significantly high compared with those of Taeumin and Soeumin. In the male group's production of vowel /i/, the Soyangin's Time Domain Total Sum /Time Domain Count, Freq Domain Total Sum /cnt(0) and 0k-4k Total Sum, Dev. were significantly high compared with those of Taeumin and Soeumin. 5) Peak In the male group's production of vowels /a/ and /i/,, the Soyangin's Peak1 Ratio was significantly low compared with that of Taeumin and Soeumin. In the male group's production of vowels /a/ and /i/,, the Soyangin's Peak10 Ratio, Time Domain Peak Total/Total Energy Sum, Time Domain Peak Dev. and Total/Total Dev. Sum were significantly high compared with those of Taeumin and Soeumin. 6) It is necessary to expand the research of the acoustic analysis of American and Korean to other countries in the diagnosis of the Sasang Constitution by using the voice characteristics.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.2
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• pp.191-205
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• 2000

The purpose of this study was undertaken to determine the effects of orthognathic surgery on speech. The hyposis stated herein is that functional behaviors of the dentofacial complex, such as speech production, may be adversely affected by deviations of a structural nature(especially, Class III malocclusion). Twenty adults with Class III malocclusion(13 female and 7 male) were studied preoperative, immediate postoperative and either 6 or 12 months postoperative lateral cephalograms. They had mandibular prognathism and had undergone mandible setback operation. The position of tongue, soft palate(Uvula), hyoid bone, respiratory track width, and pharyngeal depth were assessed on lateral cephalograms with 23 cephalometric variables, ANOVA, Paired t-tests and Pearson's product-moment correlation coefficient tests were used to evalute the operative changes in all cephalometric parameters. A experienced speech and language pathologists performed narrow phonetic transcriptions of tape-recorded words and sentences produced by each of the ninth patients and the recording tapes were analyzed by phonetic computer program(Computerized Speech Lab(CSL) Model 4300BI(U.S.A.)) These judges also recorded their ratings of each patient's overall consonants, hypernasality, hyponasality, and articulation proficiency. The results obtained are as follows; 1. There were significant changes in distance of posterior pharyngeal wall to tongue (TI-TW2, TS-TW3) after the surgery at 6 months postoperatively(each p<0.01 p<0.05). 2. The posterior tongue point(TI, TS, PPT) moved posteriorly after surgery and remained to its changed position at 6 months postoperatively(p<0.05). The displacement of tongue was correlated with the movement of mandibular setback amount(p<0.05). The hyoid bone moved posteriorly superiorly after immediate postoperative period. There was significant changes in hyoid bone movement after immediated postoperative period(p<0.05), but returned to its original position during the follow-up period(p>0.05) 3. The soft palate was displaced posteriorly superiorly after immediated operative period and remained to its changed position at 6 months postoperatively(p<0.05). ANS-PNS-SPT angle increasing, PPU-PPPo distance narrowing was showed after surgery, and remained its appearance 6 months postoperatively(p<0.05). 4. There were significant changes in formant value and squre diagram of vowel sound after the orthognathic surgery and the follow-up period. There were significant changes in /ㅅ/sound and posterior tongue sound. 5. The posterior movement of tongue and the posteriosuperior movement of soft palate was correlated with mandibular setback amount after orthognathic surgery. On the vowel squre diagram, the author found that the place of articulation after operation moved downward, backward, upward. 6. In assessing speech abnormalities, dental occlusion should be considered as a contributing factor. The vast majority of subjects with preoperative misarticulations eliminated or reduced their errors following orthognathic surgery. There was significant difference in speech impovement between pre- and postoperation.