• 음성과학
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• 제13권2호
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• pp.133-145
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• 2006

In order to understand the various groups' perceptual pattern in both VCV trochee and iambus, this study examined the identification correctness and cue robustness for the unit intervals in light of background language, age, and English listening ability. The 4 groups of Native Speakers of English, Korean College Students of High Listening Achievement, Korean College Students of Low Listening Achievement, and Korean Elementary Students took part in the experiments. Tokens of $/d{\ae}per,\;d{\ae}per,\;d{\ae}per,\;d{\ae}per,\;d{\ae}per,\;d{\ae}per$ in trochee and of $/{\eth}{\partial}\;p{\ae}d,\;{\eth}{\partial}\;b{\ae}d,\;{\eth}{\partial}\;t{\ae}d,\;{\eth}{\partial}\;d{\ae}d,\;{\eth}{\partial}\;k{\ae}d,\;{\eth}{\partial}\;g{\ae}d/$ in iambus were extracted and modified into experimental signals composed of two digits(voiced-1, voiceless-0) by following the temporal intervals, in which the signals consisted of preceding vowel, closure, VOT, and post-vowel. In the first experiment of identification correctness in VCV iambus environment, all groups showed almost 100% correctness rate, while in trochee environment all groups were different(native speaker 87%, college high 74%, college low 70%, elementary 65%). In the second experiment of cue robustness, all groups showed the similar perceptual pattern in both environments. There was the order of robustness cues in VCV trochee: pre-vowel ${\gg}$ closure ${\gg}$ VOT ${\gg}$ post-vowel, while the order in VCV iambus: VOT ${\gg}$ post-vowel ${\gg}$ closure ${\gg}$ pre-vowel. In some condition, however, we found moderately different perceptual pattern depending on language, age and listening level.

• ETRI Journal
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• 제31권4호
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• pp.451-453
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• 2009

This letter proposes the use of vowel sound detection for voice activity detection. Vowels have distinctive spectral peaks. These are likely to remain higher than their surroundings even after severe corruption. Therefore, by developing a method of detecting the spectral peaks of vowel sounds in corrupted signals, voice activity can be detected as well even in low signal-to-noise ratio (SNR) conditions. Experimental results indicate that the proposed algorithm performs reliably under various noise and low SNR conditions. This method is suitable for mobile environments where the characteristics of noise may not be known in advance.

• 말소리와 음성과학
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• 제5권3호
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• pp.31-38
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• 2013

This study investigated the influence of English vowel pronunciation training to English word-initial stop pronunciation. For that purpose, VOT values of English stops produced by twenty Korean English learners(five Youngnam dialect male speakers, five Youngnam dialect female speakers, five Kangwon dialect male speakers, and five Kangwon dialect female speakers) were measured using the Speech Analyzer and their post-training production was compared with their pre-training production. The result shows that post-training VOT values of voiced stops became closer to those of native English speakers in all four groups. Hence, it can be inferred that vowel pronunciation training is effective for correcting pronunciation of voiced vowels by analyzing the change of the quality of following vowels(especially low vowels) and the degree of giving stress.

• 대한후두음성언어의학회지
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• 제13권1호
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• pp.45-51
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• 2002

The purpose of this study is to examine the effects of vowel type on the nasalance score. Twenty one male adults without VPI produced 5 types of vowels (/a/, /e/, /i/, /o/, /u/) in two conditions-normal and simulated VPI condition. Nasalance scores were measured for each vowel. These data were compared between conditions and among vowel types. The results were as follow : For all vowels, nasalance scores were significantly higher in simulated VPI condition than in normal condition. The two conditions yielded different patterns in terms of the degree of nasalance across the 5 vowels. In normal condition, nasalance scores were higher in front vowels than in medial or back vowels. But in simulated VPI condition, nasalance scores were higher in high vowels than in mid or low vowels.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2001년도 추계학술발표논문집 (상)
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• pp.801-804
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• 2001

This article is concerned with automatic segmentation of two adjacent vowels for speech signals. All kinds of transition case of adjacent vowels can be characterized by spectrogram. Firstly the voiced-speech is extracted by the histogram analysis of vowel indicator which consists of wavelet low pass components. Secondly given phonetic transcription and transition pattern spectrogram, the voiced-speech portion which has consecutive vowels automatically segmented by the template matching. The cross-correlation function is adapted as a template matching method and the modified correlation coefficient is calculated for all frames. The largest value on the modified correlation coefficient series indicates the boundary of two consecutive vowel sounds. The experiment is performed for 154 vowel transition sets. The 154 spectrogram templates are gathered from 154 words(PRW Speech DB) and the 161 test words(PBW Speech DB) which are uttered by 5 speakers were tested. The experimental result shows the validity of the method.

• 영어영문학
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• 제57권6호
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• pp.1043-1065
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• 2011

This study investigates i-umlaut which occurred in the period of pre Old English (OE) in two aspects: what motivates i-umlaut in OE and how the phenomenon can be analyzed within the framework of OT. Unlike root-controlled vowel harmony, i-umlaut in OE is triggered by the suffixal i or j in the unstressed syllable whereby a stressed root vowel becomes fronted or raised. In this study, it is proposed that i-umlaut in OE is driven by the weak trigger i or j to improve its poor perception: I-umlaut improves the poor perceptibility of the weak trigger by extending its feature-either [-back] or [-low]-onto the vowel in the stressed syllable. This study provides an OT-theoretic analysis utilizing the licensing account to vowel harmony proposed by Walker (2004, 2005). The licensing constraints, IDENT-IO(F) and the locally conjoined constraints are proposed and their interaction correctly captures the pattern of i-umlaut in OE. Also, it is shown that the licensing account proposed in this paper is superior to the previous analyses as well as the nonlicensing approaches in that it can provide a perceptual motivation couched in i-umlaut in OE.

• 말소리와 음성과학
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• 제4권3호
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• pp.85-92
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• 2012

It is a well-known phenomenon that vowel duration in English is generally longer before a voiced stop than a voiceless one. Past research has postulated that the closure duration of the voiceless stop is generally longer than that of the voiced stop and that the duration of a preceding vowel is determined complementarily by the closure duration of the stop. To shed further light on the phenomenon, this study examined fourteen native speakers of American English who read the monosyllabic words [bVC] (V = [i, ɪ, eɪ, ɛ, æ, ʌ, ɑ], C = [t, d]). First, we found that mean vowel duration was 38 ms longer before the voiced stop than the voiceless (mean duration ratio = 1.24). Second, mean closure duration of the voiced stop was only shorter by 5 ms compared to the voiceless stop (mean duration ratio = 0.97). Therefore, for our subjects, vowel duration was not determined complementarily by the closure duration of the following stop. Third, vowels with longer inherent durations (viz., tense, diphthong, and low vowels) tended to show larger duration ratios in the voiced and voiceless contexts than the vowels with shorter durations (viz., lax vowels). This indicates that the lengthening of inherently shorter vowels before a voiced stop is limited in order to avoid overlapping with longer vowels in the duration range. Fourth, there was no significant gender difference in vowel duration ratios in the contexts of voiced and voiceless stops. Finally, considerable individual differences were found in the vowel and consonant duration ratios.

• 사상체질의학회지
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• 제19권3호
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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.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1042-1045
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• 2003

In this paper, we propose the speaker identification system that uses vowel that has speaker's characteristic. System is divided to speech feature extraction part and speaker identification part. Speech feature extraction part extracts speaker's feature. Voiced speech has the characteristic that divides speakers. For vowel extraction, formants are used in voiced speech through frequency analysis. Vowel-a that different formants is extracted in text. Pitch, formant, intensity, log area ratio, LP coefficients, cepstral coefficients are used by method to draw characteristic. The cpestral coefficients that show the best performance in speaker identification among several methods are used. Speaker identification part distinguishes speaker using Neural Network. 12 order cepstral coefficients are used learning input data. Neural Network's structure is MLP and learning algorithm is BP (Backpropagation). Hidden nodes and output nodes are incremented. The nodes in the incremental learning neural network are interconnected via weighted links and each node in a layer is generally connected to each node in the succeeding layer leaving the output node to provide output for the network. Though the vowel extract and incremental learning, the proposed system uses low learning data and reduces learning time and improves identification rate.

• 말소리와 음성과학
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• 제7권4호
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• pp.85-92
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• 2015

This study aimed to establish characteristics related to voice and speech through the natural base frequency analysis of esophagus vocalization. In the study, 8 subjects were selected for esophagus vocals, and 10 other subjects were selected for a control group. MDVP(Multi-dimensional Voice Program, Model 4800, USA, 2001), Multi Speech(Model 3700, Kaypantax, USA, 2008) were used as experiment equipment. The speech samples selected for evaluation were vowels and sentences (both declarative and interrogative). For acoustic analysis, the intonation form of fo, jitter, energy, shimmer, HNR, and intonation patterns of the speech sample were measured. The results were as follows: First, the natural intrinsic frequency of extended vowels in the esophagus vocal group was lower than the frequency in the normal vocal group. In particular, the intrinsic frequency difference for high vowel /i/ was much greater than the frequency difference for low vowel /a/. Second, the jitter values of the esophagus vocal group were higher than the control group. In particular, there was a large difference between the jitter values for /a/ and /i/, with the jitter values being highest for /i/. Third, there was no significant difference in vocal strength between the esophagus vocal patient group and the control group. Fourth, the shimmer values of the voices in the esophagus vocal group were higher than shimmer values in the control group. In particular, there was a large difference in shimmer values for low vowel /a/. Fifth, the HNR values of the esophagus vocal group were showed significantly lower than the control group. In particular, the largest difference in HNR values between the two groups was for high vowel /i/. Sixth, the pitch contours of interrogative and declarative sentences of the esophagus vocal patient group showed a different form or only had with small differences compared to the pitch contours of the normal vocal group, thus presenting an inconsistent pattern.