• 음성과학
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• 제10권2호
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• pp.145-157
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• 2003

Vowels are classified by the shapes of vocal tract. These shapes form constriction points along the tract, which have an influence on such vocal tract resonance as F1, F2, F3, and so on. The formant frequency is influenced by aperture and placement of tongue and the intensity is influenced by air pressure of subglottis. The object of this study compares to characterize the spectral outputs of oral and nasal spectra for the formant frequencies and intensity of Korean oral vowels. Subjects consisted of 20 normal persons (10 male and 10 female) without laryngeal pathology. The speech sample included /a/, /e/, /i/, /o/, /u/ of Korean oral vowels. The spectrum of each vowel was analysed by Nasal View and Real Analysis Program using Dr. Speech. The result showed that nasal intensity is decreased manifestly from F1 to F2. But oral intensity and Intensity is decreased little bit from F1 to F2. The most of values of nasal formant frequency is similarity oral formant frequency and Formant frequency or little bit smaller.

• 대한의용생체공학회:의공학회지
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• 제30권6호
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• pp.529-534
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• 2009

One of the characteristics of the hearing impaired is that their frequency selectivity is poorer than that of the normal hearing. To compensate this, formant enhancement algorithms and spectral contrast enhancement algorithms have been developed. However in some cases, these algorithms fail to improve the frequency selectivity of the hearing impaired. One of the reasons is the acoustic masking among enhanced formants. In this study, we tried to enhance the formants based on the individual masking characteristic of each subject. The masking characteristic used in this study was minimum level difference (MLD) between the first formant to the second formant while acoustic masking was occurred. If the level difference between the two formants in each frame is larger than the MLD, the gain of the first formant was decreased to reduce the acoustic masking that occurred among formants. As a result of the speech discrimination test, using formant enhanced speeches, speech discrimination score (SDS) of the speeches having differently enhanced formants was significantly superior to SDS of the speeches having equally enhanced formants. It means that suppression of the acoustic masking among formants improve frequency selectivity of the hearing impaired.

• 음성과학
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• 제13권3호
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• pp.67-82
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• 2006

The purpose of this experimental study is to investigate formant characteristics of Korean monophthongs spoken by Japanese learners and to compare the characteristics of vowels produced by the Japanese learners with those of the Korean native speakers. The data consisted of three categories: eight vowels in isolation, words including eight vowels in carrier sentences, and words including eight vowels in natural sentences. In this study, formant frequencies of the vowels were measured by Wave Surfer. It was assumed that the formant frequencies of the Korean vowels produced by the Japanese learners could be different from those of the Korean native speakers due to the influence of their own Japanese vowels. Results of this study showed that the Japanese learners had the difficulties to distinguish between the pairs /-/and /ㅜ/, /ㅓ/and /ㅗ/, and /ㅏ/and /ㅔ/. In Japanese vowels, F2 frequency value of /ㅜ/ was similar to that of the Korean /-/. It means that when the Japanese leaners produced Korean /ㅜ/, they might neutralize /-/ and /ㅜ/. Besides, there were not /ㅓ/and /ㅐ/ in Japanese vowels. Therefore, they tended to pronounce /ㅓ/ similar to /ㅗ/ which has the most similar formant frequency value with that of /ㅓ/, and /ㅐ/ was pronounced similar to /ㅔ/ for the same reason.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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• pp.2415-2418
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• 2003

In this paper, we present a new filter to adjust formant information. Spectral envelope in speech analysis shows information about characteristics of speech and formant information determines speech timbre. So, if formant position is adjusted, we can verify adjusted speech timbre. A presented filter is to adjust this formant. This filter is composed of triangular filters. Using this filter we could locate the formant frequency at target position.

• 말소리와 음성과학
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• 제9권1호
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• pp.49-53
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• 2017

Formant frequencies depend on the position of tongue, the shape of lips, and larynx. In the auditory system, the external ear canal is an open-end resonator, which can modify the voice characteristics. This study investigates the effect of the real ear on formant frequencies. Fifteen subjects ranging from 22 to 30 years of age participated in the study. This study employed three corner vowels: the low central vowel /a/, the high front vowel /i/, and the high back vowel /u/. For this study, the voice of a well-educated undergraduate who majored in speech-language pathology, was recorded with a high performance condenser microphone placed in the upper pinna and in the ear canal. Paired t-test showed that there were significant difference in the formant frequencies of F1, F2, F3, and F4 between the free field and the real ear. For /a/, all formant frequencies decreased significantly in the real ear. For /i/, F2 increased and F3 and F4 decreased. For /u/, F1 and F2 increased, but F3 and F4 decreased. It seems that these voice modifications in the real ear contribute to interpreting voice quality and understanding speech, timbre, and individual characteristics, which are influenced by the shape of the outer ear and external ear canal in such a way that formant frequencies become centralized in the vowel space.

• 전기학회논문지
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• 제66권4호
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• pp.715-720
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• 2017

This study tries to analyze morphology and formant frequencies of linear prediction spectra of stethoscope sounds for heart diseased children. For this object, heart diseased stethoscope sounds were collected in the pediatrics of an university hospital. The collected signals were preprocessed and analyzed by the Burg algorithm, a kind of linear prediction analysis. The linear prediction spectra and the formant frequencies of the spectra for the stethoscope sounds for the normal and the diseased children are estimated and compared. The spectra showed outstanding differences in morphology and formant frequencies between the normal and the diseased children. Normal children showed relatively low frequency of F1(the first formant) and small negative slope from F1. VSD children revealed stiff slope change around F1 to F3. Spectra of ASD children is similar with the normal case, but have negative values of F3. F1-F2 difference of the functional murmur children were relatively large.

• 대한의용생체공학회:의공학회지
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• 제11권2호
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• pp.283-288
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• 1990

As one of the main purpose of the physical management of cleft palate is to provide for the anatomic and physiologic requisites for speech, the speech must be as one of the criteria for determining when physical management has been achieved. But there is no objective methods to evaluate the speech of cleft palate patients. The authors tried to analyze the speech of adult cleft palate patients using sound spectrog raphy and compared with normal adults. The results were obtained as follows ; 1. In Vowels, cleft palate patients of both sexes showed reduction of frequency of the first and second formant as compared to normal. There was minimal difference in front vowels (i, e, ae) 2. In consonants, cleft palate patients showed reduction of frequency of the first formant in both sexes but reduction of frequency of the second formant was noticed only in fe- male patients. 3. There was no statistical difference in sound spectrograph between plosive, fricative, africative, nasal, and glide consonants.

• 말소리와 음성과학
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• 제4권2호
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• pp.41-49
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• 2012

The purpose of this paper is to extract the vowel formants of the ten young male speakers from the Buckeye Corpus of Conversational Speech [1] and to analyze them in comparison to earlier works in terms of various phonetic factors that are expected to affect the realization of the formant distribution. The first two formant frequency values were automatically extracted with a Praat script along with such factors as the place of articulation, the content versus function word information, syllabic stress information, the location in a word, location in utterance, speech rate of three consecutive words, and the word frequency in the corpus. The results indicated that the formant patterns from the corpus were very different from those of earlier works although the overall pattern was similar and that the factors were strongly responsible for the realization of the two formants. The purpose of this paper is to extract the vowel formants of the ten young male speakers from the Buckeye Corpus of Conversational Speech [1] and to analyze them in comparison to earlier works in terms of various phonetic factors that are expected to affect the realization of the formant distribution. The first two formant frequency values were automatically extracted with a Praat script along with such factors as the place of articulation, the content versus function word information, the syllabic stress information, the location in a word, the location in an utterance, the speech rate of the three consecutive words, and the word frequency in the corpus. The result indicated that the formant patterns from the corpus were very different from those of earlier works although the overall pattern was similar and that the factors were strongly responsible for the realization of the two formants.

• 말소리와 음성과학
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• 제10권4호
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• pp.1-10
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• 2018

This study introduces an automated Praat script allowing optimal formant analysis for children's vowels. Using Burg's algorithm in Praat, formants can be extracted by setting the maximum formant value and the number of formants. The optimal formant setting was determined by identifying the two conditions, F1 and F2, with minimum standard deviations. When applying the optimal formant setting determined by the script, the results of normality tests were not significant among all vowels except /e/ for the maximum formant value, and among the vowels /a/, /e/, /i/, /o/, /u/ and /ʌ/ for the number of formants. This indicates that when analyzing the formants of children's vowel sounds, the unilateral application of a parameter setting (the maximum formant value and the number of formants) to all vowels is problematic. The performance of the optimal formant setting script was evaluated along with 3 different algorithm in order to determine whether it properly extracts formants for children's vowels. To this end, Korean monophghongs of 6-year-old children were collected and the Praat scripts were applied to the data. Resultant Formant plots and statistical analysis showed that optimum_script and qtone_script, which links to the perceptual unit, performed very well in formant extraction compared to the remaining 2 scripts.

• 한국지능시스템학회논문지
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• 제11권6호
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• pp.510-515
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• 2001

일반적으로 음성신호로부터 사람의 감정을 인식할 수 있는 요소는(1)대화의 내용에 사용한 단어, (2)톤 (tore), (3)음성신호의 피치(Pitch), (4)포만트 주파수(Formant Frequencey)그리고 (5)말의 빠르기(Speech Speed)(6)음질(Voice Quality)등이다. 사람의 경우는주파수 같은 분석요소 보다 톤과 단어 빠르기, 음질로 감정을 받아들이게 되는것이 자연스러운 방법이므로 당연히 후자의 요소들이 감정을 분류하는데 중요한 인자로쓰일 수있다. 그리고, 종래는 주로 후자의 효소들을 이용하였는데, 기계로써 구현하기 위해서는 포만트 주파수를 사용할 수있게 되는것이 도움이 된다. 그러므로, 본 연구는 음성 신호로부터 피치와 포만트, 그리고 말의 빠르기 등을 이용하여 감성인식시스템을 구현하는것을 목표로 연구를 진행하고 있으며, 그 1단계 연구로서 본 논문에서는 화가 나서 내뱉는 말을 기반으로 하여 화난 감정의 독특한 특성을 찾아내었다.