• 말소리와 음성과학
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• 제8권3호
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• pp.51-59
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• 2016

The purpose of present study is to examine differences between habitual speech (HS) and clear speech (CS) in individuals with mild dysarthria. Twelve speakers with mild dysarthria and twelve healthy control speakers read sentences in two speaking styles. Formant and intensity related values, triangular area, and center of gravity of /a/, /i/, and /u/ were measured. In addition, formant-ratio variables such as vowel space area(VSA), vowel articulatory index (VAI), formant centralization ratio (FCR) and F2i/F1u ratio (F2 ratio) were calculated. The results of repeated-measures ANOVA showed a significant difference in F2 of vowel /i/ and F2 energy of vowel /a/ between groups. Regarding formant energy, F2 energy of vowel /a/ were observed as meaningful variables between speaking styles. There were significant speaking style-by-group interactions for F2 energy of vowel /a/. These findings indicated that current parameters could discriminate healthy group and mild dysarthria group meaningfully and that speaker with dysarthria had larger clear speech benefit than healthy talkers. We also claim that various acoustic changes of clear speech may contribute to improving vowel intelligibility.

• 말소리와 음성과학
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• 제1권4호
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• pp.171-176
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• 2009

Intelligibility measurement is one criterion for the assessment of the severity of speech disorders especially of dysarthric persons. Rate control, usually rate reduction, is used with many dysarthric speakers to improve their intelligibility. The purpose of this study is to compare how change intelligibility of speech produced by cerebral palsic speakers according to three speaking conditions. Speech samples were collected from 10 adults with cerebral palsy were asked to speak under three speaking conditions-(1) naturally(control), (2) more slowly(rate control), (3) louder and accurately(clear speech). In a perception test, after listening to the speech samples, a group of three judges were to write down whatever they heard. The result showed that total cerebral palsic subjects were divided into two subgroups according to their intelligibility according to three speaking conditions. Some subjects showed that speech intelligibility increased greatly if asked to speak 'louder and more accurately'. and the others showed no difference of intelligibility according to the speaking conditions. This study suggested that it would be useful clinically to find out the best instruction to improve intelligibility suitable for each speaker with cerebral palsy.

• 음성과학
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• 제7권2호
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• pp.177-189
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• 2000

This paper investigates how individual speakers' speech can be distinguished using acoustic parameters such as amplitude, pitch, and formant frequencies. Word samples from fifteen male speakers in their 20's in three different regions were recorded in two different modes (i.e., casual and clear speech) in quiet settings, and were analyzed with a Praat macro scrip. In order to determine individual speakers' acoustical values, the total duration of voicing segments was measured in five different timepoints. Results showed that a high correlation coefficient between $F_1\;and\;F_2$ in formant frequency was found among the speakers although there was little correlation coefficient between amplitude and pitch. Statistical grouping shows that individual speakers' voices were not reflected in regional dialects for both casual and clear speech. In addition, the difference of maximum and minimum in amplitude was about 10 dB which indicates a perceptually audible degree. These acoustic data can give some meaningful guidelines for implementing algorithms of speaker identification and speaker verification.

• 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.

• 말소리와 음성과학
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• 제13권3호
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• pp.15-20
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• 2021

In line with recent attention to the multimodal expression of politeness, the present study examined the association between polite speech and acoustic features through the analysis of vowels produced in casual and polite speech contexts in Korean. Fourteen adult native speakers of Seoul Korean produced the utterances in two social conditions to elicit polite (professor) and casual (friend) speech. Vowel duration and the first (F1) and second formants (F2) of seven sentence- and phrase-initial monophthongs were measured. The results showed that polite speech shares acoustic similarities with vowel production in clear speech: speakers showed greater vowel space expansion in polite than casual speech in an effort to enhance perceptual intelligibility. Especially, female speakers hyperarticulated (front) vowels for polite speech, independent of speech rate. The implications for the acoustic encoding of social stance in polite speech are further discussed.

• 말소리와 음성과학
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• 제4권1호
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• pp.21-28
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• 2012

Many previous studies reported acoustic parameters of English vowels produced by a clear speaking style. In everyday usage, we actually produce speech sounds with various speaking styles. Different styles may yield different acoustic measurements. This study attempts to examine pitch and formant trajectories of eleven English vowels produced by nine American males in order to understand acoustic variations depending on clear and conversational speaking styles. The author used Praat to obtain trajectories systematically at seven equidistant time points over the vowel segment while checking measurement validity. Results showed that pitch trajectories indicated distinct patterns depending on four speaking styles. Generally, higher pitch values were observed in the higher vowels and the pitch was higher in the clear speaking styles than that in the conversational styles. The same trend was observed in the three formant trajectories of front vowels and the first formant trajectories of back vowels. The second and third trajectories of back vowels revealed an opposite or inconsistent trend, which might be attributable to the coarticulation of the following consonant or lip rounding gestures. The author made a tentative conclusion that people tend to produce vowels to enhance pitch and formant differences to transmit their information clearly. Further perceptual studies on synthesized vowels with varying pitch and formant values are desirable to address the conclusion.

• 음성과학
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• 제14권2호
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• pp.91-103
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• 2007

The purpose of this paper is to develop a model enabling to predict the prosody of Korean text-to-speech synthesis using the CART and SKES algorithms. CART prefers a prediction variable in many instances. Therefore, a partition method by F-Test was applied to CART which had reduced the number of instances by grouping phonemes. Furthermore, the quality of the text-to-speech synthesis was evaluated after applying the SKES algorithm to the same data size. For the evaluation, MOS tests were performed on 30 men and women in their twenties. Results showed that the synthesized speech was improved in a more clear and natural manner by applying the SKES algorithm.

• The Journal of the Acoustical Society of Korea
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• 제19권3E호
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• pp.25-32
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• 2000

The main question addressed in this research was whether an adaptation of a standard exercise Physiology Procedure would be sensitive enough to record excess oxygen uptake associated with speech activity. Oxygen consumption was recorded for a single subject during 7-minute rest periods and an automatic speech task, also 7-minutes long and performed at three different vocal efforts. The data show measurable and systematic speech-induced modifications of breathing and oxygen uptake patterns. The subject was found to use less power for normal than for soft and loud speech. This result is similar to findings reported by experimental biologists on the energetics of locomotion. However, more comprehensive feasibility studies need to be undertaken on a larger population before solid and detailed conclusions about speech energy costs are possible. However, it appears clear that, for experimental tasks like the present one, i.e., variations in vocal effort, standard exercise physiology methods may indeed offer a viable approach to recording excess oxygen uptake associated with speech movements.

• 음성과학
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• 제7권1호
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• pp.53-64
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• 2000

Theoretically, alaryngeal speakers have difficulty in accomplishing the production of voiceless consonants. However, the perceptual studies often reveal a clear production of voiceless consonants giving good articulation scores in skilled alaryngeal speakers. The purpose of the present study was to clarify the production of voiceless stops in mode of articulation to normal speakers and skilled alaryngeal speakers. The acoustic characteristics of alaryngeal speech compared to the normal speech were investigated with special reference to the voiceless stop consonants. The surface electromyography from neck is used to monitor pharyngeal activity during speech. The general result is. that esophageal, shunt and neoglottal speakers realize the distinctions between the three types of [p] in a manner parallel to normals, whereas those using an electric voice generator do not.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.333-335
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• 2022

음성인식 처리기술의 발전은 STT, TTS 기술과 함께 각종 동영상, 스트리밍 서비스에서 적용되어 사용되고 있다. 그러나 실제 대화내용의 음성인식은 사투리 사용과 불용어, 감탄사, 유사어의 중복 등으로 명료한 문어체적 표현에 장벽이 높은 편이다. 본 연구에서는 음성인식에 모호한 사투리에 대해 범주별 사투리 중요 단어 사전 처리 방식과 사투리 운율을 음성 인식 네트워크 모델 속성으로 적용한 음성인식기술을 제안한다.