• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.746-751
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• 1991

Deafs train articulation by observing mouth of a tutor. sensing tactually the notions of the vocal organs, or using speech training aids. Present speech training aids for deafs can measure only single speech ter, or display only frequency spectra in histogrm or pseudo-color. In this study, a speech training aids that can display subject's articulation in the form of a cross section of the vocal organs and other speech parameters together in a single system Is aimed to develop and this system makes a subject to know where to correct. For our objective, first, speech production mechanism is assumed to be AR model in order to estimate articulatory notions of the vocal tract from speech signal. Next, a vocal tract profile mode using LPC analysis is made up. And using this model, articulatory notions for Korean vowels are estimated and displayed in the vocal tract profile graphics.

• Phonetics and Speech Sciences
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• v.13 no.4
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• pp.67-74
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• 2021

This study examines the effectiveness of semi-occluded vocal tract exercise (SOVTE) conducted through telepractice for 10 female teachers who have experienced vocal discomfort while working in early childhood education facilities (childcare centers, kindergartens). The effects of SOVTE conducted through telepractice were evaluated based on the Korean voice handicap index (KVHI), the Korean version of the voice activity and participation profile (K-VAPP), vocal effort, and auditory perception evaluation by using the grade, roughness, breathiness, asthenia, and strain (GRBAS) scale. The results show that total, functional, and physical scores of KVHI significantly reduced after SOVTE. The total score in K-VAPP significantly reduced after SOVTE. Moreover, vocal effort significantly decreased after SOVTE. However, statistically significant differences were not noted in GRB scales before and after SOVTE. In conclusion, early childhood teachers experienced reduced vocal discomfort SOVTE conducted through telepractice. The study results indicate that voice therapy conducted through telepractice is an effective method for reducing vocal discomfort in early childhood teachers.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2454-2456
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• 2002

Since articuratory synthesis models the human vocal organs as precise as possible, it is potentially the most desirable method to produce various words and languages. This paper proposes a new type of an articulatory synthesizer using Mermelstein vocal tract model and Kelly-Lochbaum digital filter. Previous researches have assumed that the length of the vocal tract or the number of its cross sections dose not vary while uttering. However, the continuous utterance can not be easily implemented under this assumption. The limitation is overcomed by "Buffer Rearrangement" for dynamic vocal tract in this paper.

• Phonetics and Speech Sciences
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• v.1 no.4
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• pp.195-201
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• 2009

The purpose of this study was to use high-speed digital imaging (HSDI) to compare vocal vibratory behaviors of persons who stutter (PWS) and persons with muscle tension dysphonia (PMTD) for uttering the /i/ vowel in a bid to identify the characteristics of vocal fold vibratory behaviors of PWS. This study surveyed seven developmental PWSs and seven PMTDs. The findings of the study indicated the following: first, regarding the two groups' vocal fold vibratory behaviors, of seven PWSs, three were found to be close vocal tract (VC) and four were found to be combination vocal tract (VCB). Of the seven PMTDs, one was found to be VC, and the other six were found to be VCB. These results indicate that a voiceprint which is different from the open vocal tract (VO) found in normal groups in research conducted by Jung, et al. (2008b) appeared in both groups of this study. Even between the two groups, there is a difference in the voiceprint before vocalization. Second, a VKG analysis was conducted to identify the two groups' vocal cord contact quotient. As a result, the PWS group's vocal cord contact quotient changed gradually from an irregular one at the initial vocalization stage to a regular one. The PMTD group continued the tension at the initial vocalization. Putting together all of these results, there is a difference in vocal fold vibratory behaviors between PWSs and PMTDs when they speak. Thus, there was a difference in muscular tension between the two groups.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.18 no.1
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• pp.56-61
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• 2007

Introduction: Actually classification of classic singers' voice depends on habitual judgment by voice teachers or voice trainer referring to vocal timbre, vocal range and vocal quality. Such judgments, however, may turn out to be incorrect because they are based on subjective opinions. Therefore, more objective methodology is required. Method: Foreign dissertations searched through Pub Med, along with foreign and domestic journals, were reviewed regard ing how singers' voice has been categorized. Results: Vocal range, vocal timbre, voice quality, fundamental frequency of habitual speaking, length of vocal tract, the length from cricoid cartilage to thyroid cartilage's thyroid notch and length of vocal fold, tone of passaggio as well as traditional approaches such as perceptual judgment used by professional singers have been used for categorize the voice classification. Conclusion: To optimize categorizing singers' voice, vocal range, vocal timbre, voice quality, fundamental frequency of habitual speaking, length of vocal tract, the length from cricoid cartilage to thyroid cartilage's thyroid notch and length of vocal fold, tone of passaggio may be totally recommended.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.21-24
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• 2008

The present study numerically investigates the glottal airflow characteristics as well as acoustic features of phonation fully coupled with dynamic behavior of vocal folds. The vocal folds are described by a low-dimensional body-covered model characterized by bio-mechanical parameters such as glottal width, vocal folds stiffness, and subglottal pressure. The flow in the vocal tract is modeled as an incompressible, axisymmetric form of the Navier-Stokes equations (INS), while the acoustic field is predicted by the linearized perturbed compressible equations (LPCE). The computed result shows that a two-mass model of vocal folds is sufficient to reproduce temporal variations in oral airflow and glottis motion produced by female speakers. It is also found that i) the glottal width has a significant effect on the amplitude of glottal flow, and thus on the amplitude of acoustic wave in the vocal tract, ii) the vocal fold tension is the main control parameter for the fundamental frequency of phonation, iii) the subglottal pressure plays an appreciable role on reproduction of the self-sustained oscillation of vocal folds, and iv) the strength of pulsating airflow and vortical structures are primarily affected by glottal width and subglottal pressure, and are closely related to pitch, loudness, and voice quality. Finally, more comprehensive explanation about the difference between one- and two-mass models is presented with discussion of effectiveness of vocal folds oscillation and voice quality.

• Journal of Internet Computing and Services
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• v.4 no.3
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• pp.9-14
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• 2003

The method of vocal tract normalization is a successful method for improving the accuracy of inter-speaker normalization. In this paper, we present an intra-speaker warping factor estimation based on pitch alteration utterance. The feature space distributions of untransformed speech from the pitch alteration utterance of intra-speaker would vary due to the acoustic differences of speech produced by glottis and vocal tract. The variation of utterance is two types: frequency and amplitude variation. The vocal tract normalization is frequency normalization among inter-speaker normalization methods. Therefore, we have to consider amplitude variation, and it may be possible to determine the amplitude warping factor by calculating the inverse ratio of input to reference pitch. k, the recognition results, the error rate is reduced from 0.4% to 2.3% for digit and word decoding.

• Phonetics and Speech Sciences
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• v.9 no.1
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• pp.41-47
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• 2017

The main advantage of the statistical parametric speech synthesis is its flexibility in changing voice characteristics. A personalized text-to-speech(TTS) system can be implemented by combining a speech synthesis system and a voice transformation system, and it is widely used in many application areas. It is known that the fundamental frequency and the spectral envelope of speech signal can be independently modified to convert the voice characteristics. Also it is important to maintain naturalness of the transformed speech. In this paper, a speech synthesis system based on Hidden Markov Model(HMM-based speech synthesis, HTS) using the STRAIGHT vocoder is constructed and voice transformation is conducted by modifying the fundamental frequency and spectral envelope. The fundamental frequency is transformed in a scaling method, and the spectral envelope is transformed through frequency warping method to control the speaker's vocal tract length. In particular, this study proposes a voice transformation method using the correlation between fundamental frequency and vocal tract length. Subjective evaluations were conducted to assess preference and mean opinion scores(MOS) for naturalness of synthetic speech. Experimental results showed that the proposed voice transformation method achieved higher preference than baseline systems while maintaining the naturalness of the speech quality.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.15 no.2
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• pp.98-111
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• 2004

Background and Objectives : The purpose of this study is to analyze the difference of Fundamental Frequency(Hz), Closed Quotient(Qx ; %), Intensity(dB), Vocal tract length and width(cm), formant frequency(Hz), level of formant frequency(dB) depending on the larynx position. Materials and Methods : One professional male singer(career : 28 years) produced sustained vowel /a/,/e/,/i/,/o/,/u/ in two larynx position (higher, lower) with Dr. Speech and video fluoroscopy was used to quantify the vocal tract morphology. Results : In lower larynx position, CQ is increased 9.8% and Intensity is increased about 10% and level of Formant Frequency is increased. And also Vocal tract length is longer 2.4cm, Vocal tract width(Anterior width : 0.4cm, lateral width : 0.2cm) is wider than in higher larynx position. Conclusions : Singer's formant has a prominent spectrum envelope peak near 2400-2600Hz by clustering of F3, F4 and F5 near 3400Hz in lower larynx position.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1979.05a
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• pp.8.3-8
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• 1979

Dohne (1944) has studied the consumption of air during phonation in patients with dysphonia and Arnold (1955, 1958) reported that the maximum phonation time is frequently reduced to a few seconds in paralytic dysphonia. Also, Nishikawa investigated the relation among the vital capacity, maxium phonation time, caculated mean flow rate and various vocal characteristics in patients with hoarseness. Authors have studied the aerodynamic characteristics of the vocal tract in the following aspects, using 9 L. Respirometer made in Collins Inc.; 1. Maximum phonation time 2. Maximum phonation volume 3. Mean flow rate 4. Vocal velocity index