• Speech Sciences
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• v.10 no.1
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• pp.15-25
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• 2003

A laryngograph was developed to measure the open and closed movements of vocal folds in our laboratory. This study attempted to evaluate its performance by comparing its glottal data with that of the original laryngograph. Ten normal Korean adults Participated in the experiment. Each subject produced a sustained vowel /a/ for about five seconds. This study compared f0 values, contact quotients of the duration of closed vocal folds over one glottal pulse, and area quotients of the closed over open vocal folds derived from glottal waves using both the original and new laryngographs. Results showed that the mean and standard deviation of the two laryngographs were almost comparable with a correlation coefficient 0.662 but minor systematic shift below those of the original laryngograph was observed. The absolute mean difference converged into 1 Hz, which indicates a possibility of adopting some threshold of rejecting inappropriate pitch values beyond a threshold value. The contact quotient of the normal subjects came out slightly over the 50% in a citation speech. Finally, the area quotient converged into 1. We will pursue further studies on the abnormal patients in the future.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.14 no.2
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• pp.104-109
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• 2003

The purpose of this study is to analyze the EGG measures from Lx Speech Studio program (Laryngograph Ltd, UK) in patient with vocal nodule. Thirty female adults (15 patient with vocal nodule, 15 normal speaker) produced sustained vowel and read the passage. They were grouped into three groups based on Grade (GRBAS) : normal-G0, nodule-Gl, nodule-G2. Estimates of Fx (Hz), Qx(%), Jitter, Shimmer, and HNR were made from a 500msec midportion of vowel. In addition, DFx(Hz), DQx(%), CFx(%) and CAx(%) were obtained from reading the passage. These data were compared among groups. The results were as follow Jitter, Shimmer, HNR were significantly higher in nodule-G2 group than in normal-G0 & patient-Gl group. In nodule-G2 group, CFx and CAx from reading passage were significantly higher. For patients with nodule, asymmetry or irregularity were observed in graphs of QxFx ＆ CFx provided by Quantitative Analysis.

• Speech Sciences
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• v.3
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• pp.132-147
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• 1998

Previously developed methods for pitch modification have not been based on the voice source model. Therefore, the synthesized speech often sounds unnatural although it may be highly intelligible. The purpose of this paper is to analyze the alteration of a voice source signal with pitch period and to establish the pitch-modification rule based on the result of this analysis. We examine the alteration of the interval of closing phase, closed phase and open phase using the excitation waveform as the pitch increases. In comparison to the previous methods which performed directly on the speech signal, the pitch modification method based on a voice source model shows high intelligibility and naturalness. This study might benefit the application to the speaker identification and the voice color conversion. Therefore the proposed method will provide high quality synthetic speech.

• Speech Sciences
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• v.10 no.1
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• pp.85-94
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• 2003

In this paper an algorithm to reduce the size of Text-to-Speech database is proposed. The algorithm is based on the characteristics of Korean phonemic units. From the initial database, a reduced phoneme unit set is induced by articulatory similarity of concatenating phonemes. Speech data is read by one female announcer for 1000 phonetically balanced sentences. All the recorded speech is then segmented by phoneticians. Total size of the original speech data is about 640 MB including laryngograph signal. To synthesize wave, RE-PSOLA (Residual-Excited Pitch Synchronous Overlap and Add Method) was used. The voice quality of synthesized speech was compared with original speech in terms of spectrographic informations and objective tests. The quality of the synthesized speech is not much degraded when the size of synthesis DB was reduced from 320 MB to 82 MB.

• Journal of Sasang Constitutional Medicine
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• v.12 no.1
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• pp.144-156
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• 2000

Purpose of this study is to help classifying Sasang Constitution through correlation with Larynx waveform. This study was done it under the suppose that Sasang Constitution would be correlation with Larynx waveform. The following result were obtained about correlation between Erectroglottograph waveform and Sasang Constitution by analysis EGG program. 1. Taeumin was lower than Soyangin in Open Std Deviation, Contact Std Deviation of male/a/(0.5sec) 2. Soeyangin was high compared with the others in Pitch range of maie/a/(2.5sec) 3. Taeumin was higher than Soeumin in Pitch range, Soeyangin in pitch Maximum, and the others in Pitch Std Deviation of female/e/(0.5sec) 4. Taeumin was higher than Soeumin in Contact Maximum and lower than Soeumin in Contact Maximum of female/a/(2.5sec) 5. There was no significantly difference in male/e/(0.5sec), male/e/(2.5sce), female/a/(0.5sec), female/e/(2.5sec) 6. The percent of correctly classified in Soeoumin and Taeumin was high in CART Algolism. The risk estimate of Soyangin was relatively high. The study may be use on of the method to make objective diagnosis in Sasang constitution.

• Speech Sciences
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• v.7 no.2
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• pp.193-208
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• 2000

This paper describes a multi-step method of intonation modeling for corpus-based Korean speech synthesizer. We selected 1833 sentences considering various syntactic structures and built a corresponding speech corpus uttered by a female announcer. We detected the pitch using laryngograph signals and manually marked the prosodic boundaries on recorded speech, and carried out the tagging of part-of-speech and syntactic analysis on the text. The detected pitch was separated into 3 frequency bands of low, mid, high frequency components which correspond to the baseline, the word tone, and the syllable tone. We predicted them using the CART method and the Viterbi search algorithm with a word-tone-dictionary. In the collected spoken sentences, 1500 sentences were trained and 333 sentences were tested. In the layer of word tone modeling, we compared two methods. One is to predict the word tone corresponding to the mid-frequency components directly and the other is to predict it by multiplying the ratio of the word tone to the baseline by the baseline. The former method resulted in a mean error of 12.37 Hz and the latter in one of 12.41 Hz, similar to each other. In the layer of syllable tone modeling, it resulted in a mean error rate less than 8.3% comparing with the mean pitch, 193.56 Hz of the announcer, so its performance was relatively good.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.15 no.1
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• pp.47-51
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• 2004

Normally, as a result of increased laryngeal growth, the male voice drops about one octave in pitch level during adolescence. Failure of the voice to drop in pitch is consider to be a clinically significant voice disorder - 'mutational dysphonia'. The aim of this article is to evaluate the changes brought about by voice therapy, using the analysis of the EGG measure from Lx Speech Studio program(Laryngograph Ltd, UK) as well as acoustic, and aerodynamic studies in 18-year-old mutational dysphonia patient. The results from the Lx Speech Studio program demonstrated bimodal distribution of DFx(Hz), DQx(%), QxFx and diplophonic characteristic. After voice therapy combined with manual compression method, the distribution of DFx, DQx, QxFx was changed uniform with a dramatic reduction of higher pitch level. In addition, this finding suggests the EGG measure helps to choice treatment options, monitor the efficacy of therapy, and estimate the prognosis of diseases.

• Speech Sciences
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• v.4 no.2
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• pp.157-177
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• 1998

An electroglottography (EGG) was used to investigate the function of the vocal folds during their vibration. In this study, four Korean native speakers and 10 vocal polyp patients were selected. To investigate the dynamic change of EGG waveforms for the three-way distinction of Korean stops, a DSP-Sona graph model 5500, a Rino- Laryngeal stroboscope, a CSL model 4300B and a Laryngograph were used. An EGG Model 4338 was used to exam the vocal polyp of patients' voices during high, low, comfortable pitch production. The purpose of this study is to investigate the characteristics of Korean stop consonants in relation to pitch and to observe laryngeal movement during vocal fold vibration and speech production. The basic data accumulated during this research can be applied in clinical treatment. The results are as follows: on the Korean stop consonants, the aspirated stop is the highest in the GOT and PC1. On the angle of vowel contour, the angle of lenis is smaller than the angle of heavily aspirated and glottalized stops. The fundamental frequency is lowest at the lenis stop, In vocal polyp patients', the low pitch range is smaller than in normal speakers'. The pitch break and the vocal fry were observed. The jitter and OQ value are higher in vocal polyp patients than in those of normal speakers'.

• Phonetics and Speech Sciences
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• v.1 no.1
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• pp.93-98
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• 2009

The aim of this study was to investigate voice characteristics of adductive spasmodic dysphonia(ADSD) by measuring electroglottal and acoustic examination at the sentence level. The clinical records of 86 ADSD female patients (age group of $20{\sim}50$ years) and the control records of 86 normal females (age group of $20{\sim}40$ years) were recorded by speech studio(Laryngograph Ltd., UK). An independent t-test was used to compare ADSD and normal group. Results were as follows. (1) Fundamental frequency($F_0$) was significantly decreased in ADSD compared with normal group. (2) Irregularity of frequency and closed quotient(CQ) was significantly increased in ADSD compared with normal group. (3) Voiceless duration increased and voiced duration was significantly decreased in ADSD compared with normal group. (4) Fricative duration was increased in ADSD compared with normal group but it wasn't significant. In conclusion, strained, tight and choked voice shows an increase of CQ, tremor voice shows an increase of irregularity of frequency and less feminine voice shows decrease of $F_0$. Increase of voiceless duration and fricative duration and decrease of voiced duration related with diminution speech intelligibility.

• Speech Sciences
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• v.10 no.2
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• pp.111-128
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• 2003

Aerodynamic study is valuable information about the vocal efficiency in translating airflow to acoustic signal. The purpose of this study was to investigate the differences between trained singers and untrained controls under different two pitch by simultaneous using the airway interruption method and electroglottography (EGG). Under singing a Korean lied 'Gene', 20 (Male 10, Female 10) trained singers were studied on two one-octave different tone. Mean flow rate (MFR) , subglottic pressure (Psub) and intensity were measured with aerodynamic test using the Phonatory function analyzer (Nagashima Ltd. Model PS 77H, Tokyo, Japan). Closed quotients (Qx), jitter and shimmer were also investigated by electroglottography using Lx speech studio (Laryngograph Ltd, London, UK). These data were compared with those of normal controls. MFR and Psub were increased on high pitch tone in all subject groups. Statistically significant increasing of Qx and intensity were observed in male trained singers on high pitch tone (Qx;p = .025, intensity;p < .001). Beacasue of increasing of Qx and intensity, vocal efficiency was also significantly increased in male singers (p < .001). The trained singers' phonation was more efficient than untrained singers. The result means that the trained singers can increase the loudness with little changing of mean flow rate, subglottic pressure but more increasing of glottic closed quotients.