• 대한음성학회지:말소리
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• 제64호
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• pp.1-14
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• 2007

The purpose of this study was to examine the acoustic perception different by formants change for profoundly hearing impaired children with cochlear implants. The subjects were 10 children after 15 months of experience with the implant and mean of their chronological age was 8.4 years and Standard deviation was 2.9 years. The ability of auditory perception was assessed using acoustic-synthetic vowels. The acoustic-synthetic vowel was combined with F1, F2, and F3 into a vowel and produced 42 synthetic sound, using Speech GUI(Graphic User Interface) program. The data was deal with clustering analysis and on-line analytical processing for perception ability of acoustic synthetic vowel. The results showed that auditory perception scores of acoustic-synthetic vowels for cochlear implanted children were increased in F2 synthetic vowels compaire to those of F1. And it was found that they perceived the differences of vowels in terms of distance rates between F1 and F2 in specific vowel.

• 말소리와 음성과학
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• 제6권3호
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• pp.81-89
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• 2014

Korean English learners tend to have difficulty perceiving and producing English vowels. The purpose of this study is to examine a link between perceived and produced vowel spaces of Korean learners of English. Sixteen Korean male and female participants perceived two sets of English synthetic vowels on a computer monitor and rated their naturalness. The same participants produced English vowels in a carrier sentence with high and low pitch variation in a clear speaking mode. The author compared the perceived and produced vowel spaces in terms of the pitch and gender variables. Results showed that the perceived vowel spaces were not significantly different in either variables. Korean learners perceived the vowels similarly. They did not differentiate the tense-lax vowel pairs nor the low vowels. Secondly, the produced vowel spaces of the male and female groups showed a 25% difference which may have come from their physiological differences in the vocal tract length. Thirdly, the comparison of the perceived and produced vowel spaces revealed that although the vowel space patterns of the Korean male and female learners appeared similar, which may lead to a relative link between perception and production, statistical differences existed in some vowels because of the acoustical properties of the synthetic vowels, which may lead to an independent link. The author concluded that any comparison between the perceived and produced vowel space of nonnative speakers should be made cautiously. Further studies would be desirable to examine how Koreans would perceive different sets of synthetic vowels.

• 말소리와 음성과학
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• 제5권3호
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• pp.39-46
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• 2013

This study examined the perception of two Korean vowels using F1/F2 manipulated synthetic vowels. Previous studies indicated that there is an overlap between the acoustic spaces of Korean /o/ and /u/ in terms of the first two formants. A continuum of eleven synthetic vowels were used as stimuli. The experiment consisted of three tasks: an /o/ identification task (Yes-no), an /u/ identification task (Yes-no), and a forced choice identification task (/o/-/u/). ROC(Receiver Operating Characteristic) analysis and logistic regression were performed to calculate the boundary criterion of the two vowels along the stimulus continuum, and to predict the perceptual judgment on F1 and F2. The result indicated that the location between stimulus no.5 (F1 = 342Hz, F2 = 691Hz) and no.6 (F1 = 336Hz, F2 = 700Hz) was estimated as a perceptual boundary region between /o/ and /u/, while stimulus no.0 (F1=405Hz, F2=666Hz) and no.10 (F1=321Hz, F2=743Hz) were at opposite ends of the continuum. The influence of F2 was predominant over F1 on the perception of the vowel categories.

• 대한전자공학회논문지
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• 제27권10호
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• pp.138-145
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• 1990

본 논문에서는 합성단위를 반음절로 하여 적은 데이터 베이스를 차지하면서도, 합성음의 자연스러움을 향상 시키기 위한 한국어 규칙 합성법을 제시한다. 반음절 음성신호를 분석하기 위해 12차 선형 예측법을 사용하며, 합성음의 자연성과 명료성을 위해 음절간 접속 규칙, 모음부의 연결규칙을 개발한다. 또한 신경망 모델을 이용한 음운 변동 규칙과 운율규칙을 적용한다.

• 한국문헌정보학회지
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• 제1권
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• pp.1-58
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• 1970

As to the structure of author tables for the Korean libraries using the Korean alphabet Hangul for filing, no other system is understood more relevant to author notations than the analytico-synthetic system. The Korean character consists of syllables respectively dividual into 'consonant+vowel' or 'consonant+vowel+consonant,' with the first element a consonant and the second a vowel. When these elements are synthesized with figure representation, they make an enumerative two-figure table. Individualizing and assigning, therefore, are done without listing many en-tries on the table or looking up notations in ready-made enumerative author tables. We still do not have general agreements in form of entry, reading of the Japanese and Chinese names, transliteration of foreign words, and filing system. What is more, so flexible and hospitable a notation system should be adopted as to meet the anticipated changes. The writer introduces an author notation system that could make 150,000 divisions by combinating figures, thus making it possible to endure changes through readjustments. It is considered effective, convenient, and efficacious for individualization.

• 말소리와 음성과학
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• 제6권4호
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• pp.91-99
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• 2014

Speaking styles tend to have an influence on spectral characteristics of produced speech. There are not many studies on the spectral characteristics of speech because of complicated processing of too much spectral data. The purpose of this study was to examine spectral characteristics and formant bandwidths of English vowels produced by nine American males with different speaking styles: clear or conversational styles; high- or low-pitched voices. Praat was used to collect pitch-corrected long-term averaged spectra and bandwidths of the first two formants of eleven vowels in the speaking styles. Results showed that the spectral characteristics of the vowels varied systematically according to the speaking styles. The clear speech showed higher spectral energy of the vowels than that of the conversational speech while the high-pitched voice did the same over the low-pitched voice. In addition, front and back vowel groups showed different spectral characteristics. Secondly, there was no statistically significant difference between B1 and B2 in the speaking styles. B1 was generally lower than B2 when reflecting the source spectrum and radiation effect. However, there was a statistically significant difference in B2 between the front and back vowel groups. The author concluded that spectral characteristics reflect speaking styles systematically while bandwidths measured at a few formant frequency points do not reveal style differences properly. Further studies would be desirable to examine how people would evaluate different sets of synthetic vowels with spectral characteristics or with bandwidths modified.

• 한국통신학회논문지
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• 제10권4호
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• pp.159-167
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• 1985

男性話者가 發音한 韓國語 母音/아, 에, 이, 오, 우/의 聲門波를 직접 抽出하여 音聲에 따라 성문파가 각각 다르다는 것을 확인하였다. 具現한 5가지의 성문파로 母音을 다시 合成하여 聲門波形이 音聲合成에 미치는 영향을 波形的으로 비교하였다. 상문파의 모양, 개방시간과 폐쇄기간에 따라 合成音聲波形은 變化가 있었으며, 聲門波形이 合成音質向上의 중요 factor로 作用함을 알 수 있었다.

• 한국음향학회지
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• 제25권5호
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• pp.213-221
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• 2006

합성음의 음질을 향상시키기 위하여 분할된 corpora로부터 합성유닛을 선택하여 사용하는 연속음성합성에서 정확한 음소분할은 매우 중요하다. 일반적으로 음소분할은 사람에 의해 수행되지만 많은 작업량으로 인한 시간적 지연, 일관 성 유지 어려움 등 많은 문제가 발생한다. 이에 따라 음성인식에서 도입된 HMM 기반의 자동음소분할이 음성인식, 음성 합성에서 널리 사용되어지고 있지만 음성전문가의 수작업 결과와 비교할 때 HMM 기반 자동음소분할은 오류가 있고, 이는 합성음 품질의 열화의 주요 원인이 되고 있다. 본 논문에서는 HMM 기반의 자동음소분할기를 사용하여 나타난 자동음소분할 결과와 수작업에 의한 음소분할 결과를 비교하고 유형별로 분석함으로써 음성합성의 성능향상을 위해 개선해야 할 문제점들을 제시한다. 실험에서는 ETRI의 표준형 한국어 공통 음성 DB을 사용하였고, 오차의 범위가 20ms를 벗어난 경우를 분절 오류로 간주하였다. 실험 결과 여성화자의 경우 파열음 + 모음, 파찰음 + 모음, 모음 + 유음 음소쌍에서는 각각 약 99%, 99.5%, 99%의 높은 정확률을 보인 반면, 폐쇄음 + 비음, 폐쇄음 + 유음, 비음 + 유음 음소쌍에서는 44.89%, 50%, 55% 의 낮은 정확률을 보였으며, 남성화자에 대한 실험결과에서도 유사한 경향을 보였다.

• 한국음향학회지
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• 제18권7호
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• pp.10-16
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• 1999

본 논문에서는 설계하지 않은 연속 음성 코퍼스로부터 추출된 CVC 음성 세그먼트를 사용하는 연결 기반 음성 합성기를 제안한다. 연속 음성은 각 음운간의 상호조음효과가 비교적 잘 반영되고, 자연스러운 억양 변화를 포함하고 있으므로 이를 적절하게 활용할 수 있는 합성 단위를 선택하면 자연스런 음성합성이 가능하다. 여러 가지 합성단위 가운데 CVC 합성 단위는 자음의 안정 부분에서 접속이 일어나므로 연결부에서의 음질 저하가 적고, 전후 자음과 모음간의 조음 현상을 잘 반영하는 장점이 있다. 본 논문에서는 CVC 합성 단위를 사용하는 경우 나타나는 문장 세그먼트들의 조합을 4가지로 분류하여 각각의 통계적 특성과 합성음성의 품질을 분석하고, CVC에 근거한 새로운 복합 합성 단위를 사용하는 방식을 제안한다. 제안된 방식을 사용하여 설계하지 않은 연속 음성 코퍼스로부터 CVC 음성 세그먼트를 추출하여 다양한 예제 문장을 합성하였다. 만일 필요한 CVC 음성 세그먼트가 음성 코퍼스에 존재하지 않는 경우 반음절 음성 세그먼트로 대치하여 합성하였다. 실험 결과 약 100 Mbytes의 연속 음성 코퍼스로 비교적 자연스러운 음성합성이 가능함을 알 수 있었다.

• 말소리와 음성과학
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• 제7권1호
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• pp.21-26
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• 2015

The aim of this study is to synthesize pathological breathy voice and to make a cepstral peak prominence (CPP) table following breathiness ranks by cepstral analysis to supplement reliability of the perceptual auditory judgment task. KlattGrid synthesizer included in Praat was used. Synthesis parameters consist of two groups, i.e., constants and variables. Constant parameters are pitch, amplitude, flutter, open phase, oral formant and bandwidth. Variable parameters are breathiness (BR), aspiration amplitude (AH), and spectral tilt (TL). Five hundred sixty samples of synthetic breathy vowel /a/ for male were created. Three raters participated in ranking of the breathiness. 217 were proved to be inadequate samples from perceptual judgment and cepstral analysis. Finally, 343 samples were selected. These CPP values and other related parameters from cepstral analysis are classified under four breathiness ranks (B0~B3). The mean and standard deviation of CPP is $16.10{\pm}1.15$ dB(B0), $13.68{\pm}1.34$ dB(B1), $10.97{\pm}1.41$ dB(B2), and $3.03{\pm}4.07$ dB(B3). The value of CPP decreases toward the severe group of breathiness because there is a lot of noise and a small quantity of harmonics.