• 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.

• 한국산학기술학회논문지
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• 제12권12호
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• pp.5588-5593
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• 2011

본 논문에서는 심장에 해당하는 이(耳)혈 상응점을 자극하여 심장과 관련된 음성분석 요소의 변화를 측정하였다. 이를 위해 심장에 이상이 없는 피실험자 10명을 선정하고 심장에 해당하는 이혈 상응점을 자극하기 전과 후의 음성을 수집하였다. 실험은 음성분석 요소 중 심장과 관련된 Jitter와 2 Formant Frequency Bandwidths를 적용하여 심장 이혈 자극 전과 후의 변화를 측정, 분석하였다. 실험 결과 90%의 피실험자가 Jitter와 2 Formant Frequency Bandwidths 값이 감소하는 현상을 보였으며 이를 통해 이혈 자극에 따른 심장과 음성의 상관성을 분석할 수 있었다. 끝으로 실험에 의해 제안한 방법의 유용성을 입증하고자 한다.

• 말소리와 음성과학
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• 제6권2호
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• pp.55-64
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• 2014

This study measured formant bandwidths of profound hearing impaired children and examined the characteristics of their articulation. For this study, 10 cochlear implanted children(CI), 10 hearing aid children(HA) and 10 normal hearing children(NH) were asked to read 7 Korean vowels(/ɑ, ʌ, o, u, ɯ, i, ɛ/). The subjects' readings were recorded by NasalView and analyzed by Praat. The analysis of the formant bandwidths explains the degree of vocal fold opening and the characteristics of radiation. Through the analysis of formant bandwidth, we can see that the hearing-impaired maintain vocal fold tension when they speak high vowels and characteristics of radiation. Narrower B1 means better maintain vocal fold tension, wider B2 means more front and wider B3 means the rounder lips. CI's B1 was widest and NH's was narrowest. And females' B1 was wider than males'. Among vowels, B1 of /a/ was widest, and B1 of /i/ was narrowest. In the case of B2, HA and NH's B2 was wider than CI's. Females' B2 was wider than males'. And B2 of /i/ was widest, and B2 of /ʌ/ was narrowest. In the case of B3, NH's was widest, and CI's was narrowest. Males' was wider than females'. Among vowels, B3 of /o/ was widest, and B3 of /ɛ/ was narrowest. As a result, first, through the analysis of B1, we can find that NH and males could better maintain vocal fold tension than the hearing-impaired or females, and all children articulate /i/ with vocal fold tension than other vowels. Second, through the analysis of B2, NH and HA articulate vowels with the weaker rounded than CI does. And females articulate vowels with the weaker rounded than males do. Third, through the analysis of B3, NH articulate vowels with the rounder than HA or CI do, and males articulate vowels with the rounder than females do. Through the results, we can expect that the analysis of formant bandwidth will be applied to the therapy of articulation for the hearing-impaired with hearing aids or cochlear implant.

• 대한후두음성언어의학회지
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• 제9권1호
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• pp.27-31
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• 1998

Nasal sounds include nasalized vowels and consonants. Nasal cavity is important for the acoustics of nasal sounds. Evaluating the effects of site-specific nasal obstruction on nasal sound will help us to understand the importance of nasal geometry for the nasal sound and to foretell voice change after nasal surgery This study was designed to analyze the change of nasality and formant characteristics of nasal sound by obstructing different sites around the ostiomeatal unit(OMU). Ten adult male and female volunteers participated. The nasal formants and bandwidths of nasal consonant /n/ were checked in various conditions of nasal obstruction. The nasalance of rabbit, baby, and mama passages were compared in each conditions. Nasalance of all passages decreased when anterior portion of OMU was obstructed. Center frequency of first nasal formant(NF1) of /n/ has decreased in the order of anterior, inferior obstruction. The bandwidth of NF1 decreased in female with anterior obstruction. Anterior portion of OMU is most critical to the change of nasality and acoustics of nasal consonant. When anterior portion of OMU is obstructed, the shift of NF1 to a lower frequency and the narrowing of NF1 bandwidth are the major acoustic changes of nasal consonant /n/.

• 한국음향학회지
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• 제21권4호
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• pp.361-373
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• 2002

본 논문에서는 음성 인식과 화자 인식에서 채널 변이 정규화를 위해 널리 사용되는 전통적인 켑스트럴 평균차감법 (CMS: Cepstral Mean Subtraction)의 성능을 향상시키기 위한 정규화 방법을 제안한다. 기존의 켑스트럴 평균 차감법은 장구간 켑스트럼의 평균으로 채널 성분을 추정하므로 유성음의 포먼트에 의해 채널 성분이 편향되는 단점을 가진다. 제안된 포먼트 평활화 켑스트럴 평균 차감법 (FBCMS; Formant-broadened CMS)은 켑스트럼으로부터 변환된 로그 스펙트럼에서 포먼트 위치를 쉽게 찾을 수 있고, 포먼트는 전극점 모델로 표현되는 성도 전달 함수의 우세 극점에 대응된다는 사실에 근거한다. 따라서 제안된 방법은 켑스트럼으로부터 음성의 포먼트를 구하고, 이로부터 포먼트의 대역폭을 확장한 켑스트럼을 구한 후 평균함으로써 채널 켑스트럼 성분으로부터 우세 극점들의 영향을 제거한다. 전극점 모델의 우세 극점을 얻기 위해 다항식 인수분해 과정을 거치지 않으므로 연산량을 줄일 수 있으며 포먼트에 해당하는 우세 극점만으로 선택적으로 처리할 수 있다. 본 연구에서는 4가지의 모의 채널을 이용하여 전통적인 켑스트럴 평균 차감법, 극점 필터화 켑스트럴 평균 차감법 (Pole-filtered CMS) 그리고 제안된 방법의 비교실험을 수행하였다. 실제 채널 켑스트럼과 추정된 채널 켑스트럼과의 거리를 측정하는 실험에서 음성에 의한 편향을 완화시켜 실제 채널에 보다 가까운 평균 켑스트럼을 얻을 수 있음을 확인하였다. 또한 문장독립 화자 식별에서 제안된 방법은 전통적인 켑스트럴 평균 차감법보다 우세하고 극점 필터화 켑스트럴 평균 차감법 (Pole-filtered CU)과는 비슷한 결과를 보였다. 결과적으로 제안된 방법은 전통적인 켑스트럴 평균 차감법에 기반하여 효과적인 채널 정규화가 가능하다는 것을 보였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권1호
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• pp.13-20
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• 2006

The articulation disorders associated with velopharyngeal insufficiency (VPI) in cleft palate patients are interested to clinicians particularly. The purpose of this study was to investigate mainly the oropharyngeal air pressure and overall air flow in cleft palate patients. The pressure-measuring catheter was positioned at the midportion of the oropharyngeal cavity with a facial mask. Test words were composed of 9 meaningless polysyllabic words and 17 meaningful words. Aerophone II and Nasometer II were used to measure peak air pressure, mean air pressure, maximum flow rate, volume, phonatory flow rate, nasalance. The data shows that airflow of the cleft palate patient group were higher than those of the control group. Intraoral air pressure of the cleft palate patient group was lower than those of the control group. The first vowel formant and first Bandwidths of the cleft palate patient group were higher than those of the control group.

• 정보처리학회논문지B
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• 제18B권6호
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• pp.389-396
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• 2011

현대 사회에서 식습관의 변화, 스트레스, 음주 등으로 인해 다양한 간 질환이 발생되거나 악화되어 가고 있다. 따라서 본 논문에서는 간 질환이 음성에 미치는 영향을 연구하여 간 질환을 조기에 진단할 수 있는 방법론을 제안하였다. 이를 위해 간 질환자를 대상으로 입원했을 때와 치료로 인해 정상적으로 퇴원했을 때의 음성을 각각 수집하여 음성 분석 요소를 적용한 실험을 수행하였다. 특히, 한의학적으로 간(肝)과 관련 있는 발음인 아음(牙音)에 대한 분석 실험으로 제3포먼트 주파수 대역폭과 발음 요소값을 적용한 실험을 수행하였으며 이를 통해 간 질환이 공명강과 발성에 미치는 영향을 객관적 지표로 출력하는 연구를 행하였다. 또한 실험 결과를 기반으로 u-Health 환경에서 간 기능을 모니터링하는 시스템 설계에 관한 연구를 수행하였다.

• 음성과학
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• 제2권
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• pp.25-44
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• 1997

When listening the various speech synthesis systems developed and being used in our country, we find that though the quality of these systems has improved, they lack naturalness. Moreover, since the voice color of these systems are limited to only one recorded speech DB, it is necessary to record another speech DB to create different voice colors. 'Voice Color' is an abstract concept that characterizes voice personality. So speech synthesis systems need a voice color control function to create various voices. The aim of this study is to examine several factors of voice color control rules for the text-to-speech system which makes natural and various voice types for the sounding of synthetic speech. In order to find such rules from natural speech, glottal source parameters and frequency characteristics of the vocal tract for several voice colors have been studied. In this paper voice colors were catalogued as: deep, sonorous, thick, soft, harsh, high tone, shrill, and weak. For the voice source model, the LF-model was used and for the frequency characteristics of vocal tract, the formant frequencies, bandwidths, and amplitudes were used. These acoustic parameters were tested through multiple regression analysis to achieve the general relation between these parameters and voice colors.