• Speech Sciences
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• v.10 no.2
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• pp.129-143
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• 2003

Fundamental frequency (Fo), jitter, shimmer, and harmonics-to-noise ratio (NHR) have been measured to see their interactions between the parameters using Multi-Dimensional Voice Program (MDVP). 100 Korean normal adults (50 males and 50 females) ranging from their early 20's to their early 30's produced the eight sustained vowels including /a/, /i/, /u/, /c/, /e/,/$\varepsilon$/, /i/, and /e/. The subjects were asked to read the above vowels five times in isolation with the interval of five seconds, respectively. Male voices, on the average, showed 130.7 Hz in Fo, 0.6696% in jitter, 1.8151% in shimmer, and 0.12 in NHR, while female voices showed 232.8 Hz in Fo, 0.9222% in jitter, 1.9199% in shimmer, and 0.1098 in NHR. As to the correlation coefficient, it was found that for male speakers jitter vs. shimmer, shimmer vs. NHR, Fo vs. shimmer, and Fo vs. NHR are statistically significant. It was found that for female subjects jitter vs. shimmer and Fo vs. shimmer are statistically significant. However, it is concluded that the correlation coefficient in females are not meaningful in a practical way though they are all statistically significant.

• Speech Sciences
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• v.10 no.1
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• pp.143-152
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• 2003

The present study was performed to investigate change in shimmer according to $F_{0}$ variation precisely, and to offer suggestions for a clinical application. The analysis for the present study was done by the fundamental frequency ($F_{0}$) and shimmer measurement results of the previous 120 Korean normal adults' voice study of Pyo et al. (2002), used three vowels, /i/, /a/, /and /u/. Through the analysis of 60 female samples from the previous study, we found that $F_{0}$ of the vowels was the highest in /u/, and the lowest in /a/, but, on the contrary, shimmer was highest in /a/and lowest in /u/. Thirty of 60 subjects showed such an inverse relationship between $F_{0}$ and shimmer, as a whole. In the vowel /a/, 47 of 60 subjects showed the increased $F_{0}$ and decreased shimmer, in /i/, 32 subjects, and in /u/, 33 subjects showed the same results. The decrease in shimmer means the improvement of voice quality, so by these results, we expect to answer the question why the patients with spasmodic dysphonia can improve their voice quality with increased pitched voice production.

• Phonetics and Speech Sciences
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• v.6 no.2
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• pp.107-114
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• 2014

MDVP and Praat are measured by nine variables in common; F0, jitter local, jitter absolute, jitter relative average perturbation, jitter period perturbation quotient, shimmer local, shimmer dB, shimmer amplitude perturbation quotient, and NHR. In the present study, 30 female subjects were divided by their disorders(control group, vocal nodule group), ages(from 18 to 50 years old), gender(women), and severities of voice disorder(GRBAS-G0, G1, G2). Then, the subjects' vowel /a/ was evaluated by MDVP and Praat. First, jitter and shimmer variables of the MDVP were significantly different by severities. Praat showed different jitter, shimmer, and NHR parameters by severities. Second, jitter and NHR levels of MDVP were meaningfully higher than Praat regardless their severities. The result of the research confirms the relationships among GRBAS, MDVP and Praat as well as the differences in acoustic variables between MDVP and Praat.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.11
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• pp.5541-5554
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• 2018

A voice is one of the most significant non-verbal elements for communication. Disorders in vocal organs, or habitual muscular setting for articulatory cause vocal disorders. Therefore, by analyzing the vocal disorders, it is possible to predicate vocal diseases. In this paper, a method of predicting vocal disorders using the jitter, shimmer, and harmonics-to-noise ratio (HNR) extracted from vocal records is proposed. In order to extract jitter, shimmer, and HNR, one-second's voice signals are recorded in 44.1khz. In an experiment, 151 voice records are collected. The collected data set is clustered using cobweb clustering method. 21 classes with 12 leaves are resulted from the data set. According to the semantics of jitter, shimmer, and HNR, the class whose centroid has lowest jitter and shimmer, and highest HNR becomes the normal vocal group. The risk of vocal disorders can be predicted by measuring the distance and direction between the centroids.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.5 no.1
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• pp.38-43
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• 1994

Though normal vocal cords show regular vibration, pathologic vocal cords show irregularity between peaks. Jitter means fluctuation in the time interval between peaks, and Shimmer means cycle to cycle variation in the amplitude of the peaks. We investigated the vocal vibration of Korean normal persons objectively. The fundamental frequency, Jitter, Shimmer and SNR(signal to noise ratio) of normal persons were compared with that of vocal Polyp Patients with CSpeech Program for the possibility of distinguishing the pathologic vocal vibration from normal. The results were as follows ; Comparing the fundamental frequency of vocal Polyp Patients with normal persons, great change was noted only in female cases. But the Jitter and Shimmer of vocal polyp patients were greater than normal significantly in both male and female cases. SNR was lower than normal in vocal polyp patients. In the conclusion, fundamental frequency, Jitter, Shimmer and SNR might be meaningful parameters distinguisuing pathologic vibration from normal.

• Speech Sciences
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• v.10 no.3
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• pp.29-36
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• 2003

The purposes of this study was to conduct a correlational analysis among $F_^{0}$, Jitter, Shimmer, and NHR (HNR), and NNE estimated by three speech analysis softwares, MDVP, Praat and Dr. Speech. Thirty females and 15 males with normal voice participated in the study. We used Sound Forge 6.0 to record their voice. MDVP, Praat and Dr. Speech were used to measure the acoustic parameters. The Pearson correlation coefficient was determined through a statistical analysis. The results came out as follows: Firstly, there was a strong correlation between $F_^{0}$ and Shimmer of both instruments. However, there was no correlation between Jitter of both instruments. Secondly, Shimmer showed a stronger correlation with HNR, NHR, and NNE than Jitter. Therefore, Shimmer was considered to be more useful and sensitive parameter to identify dysphonic voice compared to jitter.

• Phonetics and Speech Sciences
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• v.7 no.4
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• pp.59-65
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• 2015

This study was conducted to identify the differences in voice characteristic variables before and after taking a certain amount of high-caffeine. Linear PCM-M10 Recorder (SONY) was used for the recorder and basic frequency of the voice (Fo), frequency fluctuation rate (jitter), amplitude fluctuation rate (shimmer) and Signal-to-Noise Ratio (SNR) were measured using TF-32(University of Wisconsin-Madison, USA). First, prolonged phonation analysis results of /ah/ by male subjects showed the shimmer values after taking high-caffeine increased statistically significantly(p<.05) compared with before the intake and SNR values significantly decreased. (p<.05). On the other hand, female subjects didn't show any statistically significant differences in all variables. Second, male subjects showed statistically significant increased shimmer values after the intake compared with before the intake at /ah/ of syllable 'na' and /ah/ in 'ra' in 'autumn' paragraph (p<.05), and jitter values significantly increased at /ah/ in 'ah' (p<.05). However, female subjects didn't show any statistically significant differences in all variables. Results of this study showed that high-caffeine intake more affects male subjects than female subjects. In male subjects, shimmer and SNR changed at vowel prolonged phonation, /ah/, and study results showed that shimmer and SNR in 'Autumn' paragraph /na/, /ra/ and jitter in /ah/ could be identified as the variables to show the voice change.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.14 no.1
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• pp.16-25
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• 2003

Background and Objectives : Electroglottography(EGG) is a non-invasive method of monitoring the vocal cord vibration by measuring the variation of physiological impedance across the vocal folds through the neck skin. It reveals especially the vocal fold contact area and is widely used for basic laryngeal researches, voice analysis and synthesis. The purpose of this study is to investigate the effectiveness of EGG parameters in differential diagnosis of laryngeal cancer. Materials and Methods : The author investigated 10 laryngeal cancer and 25 benign laryngeal disease patients who visited at the Department of Otolaryngology, Pusan National University Hospital. The EGG equipment was devised in the author's Department. Among various parameters of EGG, closed quotient(CQ), speed quotient(SQ), speed index(SI), Jitter, Shimmer, Fo were determined by an analysis program made with MATLAB 6.5$^{\circledR}$(Mathwork, Inc.). In order to differentiate various laryngeal diseases from pathologic voice signals, the author has used the electroglottographic parameters using the neural network of multilayer perceptron structure. Results : SQ, SI, Jitter and Shimmer values except those of CQ and Fo showed remarkable differences between benign and malignant laryngeal disease groups. From the artificial neural network, the percentage of differentiating the laryngeal cancer was over 80% in SQ, SI, Jitter, Shimmer except for CQ and Fo. These results indicated that it is possible to discriminate the benign and malignant laryngeal diseases by EGG parameters using the artificial neural network. Conclusion : If parameters of EGG which can reveal for the pathology of laryngeal diseases are additionally developed and the current classification algorithm is improved, the discrimination of laryngeal cancer will become much more accurate.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.8 no.2
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• pp.166-172
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• 1997

Background : For example, aerodynamic study, vibratory study, acoustic study, neuro-muscular test and psychoacoustic evaluation, a number of objective methods are now available for assessing pathologic voice change. They help to differentiate pathologic condition from normal condition and to monitor pathologic and aging change. These laboratory analyses are used commonly to monitor speech therapy and to follow a patient's recovery after surgery. Objectives : We investigated the values of jitter, shimmer and NNE of normal person and hoarseness patients in Korea. The values of Jitter and shimmer might be meaningful parameters distinguishing pathologic vibration from normal and recovery after surgery. Materials and Methods : Statistical significance between normal control and 48 subjects taken microlaryngeal surgery were compared with Dr. speech science program that is computerized system for acoustic analysis of voice production employed to determine vocal characteristics of pitch perturbation(jitter) and amplitude perturbation(shimmer). Results : The mean normal values of jitter and shimmer were 0.226${\pm}$0.110(%), 2.200${\pm}$0.421(%) in male and 0.164${\pm}$0.060(%), 2.063 ${\pm}$0.575(%) in female. In patients with vocal nodule, the preoperative and postoperative values of jitter and shimmer were valueless. In patients with vocal polyps, the preoperative and postoperative values of jitter and shimmer were valuable. Conclusion : Dr. speech science program was effective to monitor laryngeal disease and aging changes.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.7 no.1
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• pp.39-42
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• 1996

The present study analyed jitter and shimmer of the deaf in 4 different voicing conditions. Thirty-two male subjects and 27 female subjects participated in the study on a voluntary basis. The age ranged from 6 to 18 for male and 8 to 21 for female subjects. The subjects were either congenitally or prelingually deaf The four different voicing conditions included /a/ prolongation, counting, reading, and conversation. The experiment utilized CSL Visi-Pitch Model 6095(Kay Elemetrics Corp.) to sample and analyze the data. Both jitter and shimmer means were higher than the threshold values(normative data) reported. In addition, this investigation performed two separate 2-factor ANOVAs in order to determine if jitter and shimmer change as a function of gender and voicing condition. The results showed the following. First of all there was the gender effect on shimmer but not on jitter, in that male subjects 'shimmer was higher than females'. secondly, there was the voicing condition effect both on jitter and shimmer. /a/ prolongation and reading produced lower jitter than counting and conversation. /a/ prolongation produced lower shimmer than the remaining conditions. Finally, no interaction between gender and voicing condition existed.