• 말소리와 음성과학
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• 제2권1호
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• pp.113-120
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• 2010

In this paper, we investigate the acoustic characteristics of sustained voices from normal subjects and patients with laryngeal pathologies. Perturbation methods (including jitter and shimmer), signal-to-noise ratio (SNR), and nonlinear dynamic methods (such as correlation dimension) are used to analyze normal and pathological voices. We find that jitter does not statistically discriminate between normal and pathological voices, but a significant difference is found for shimmer, SNR, and correlation dimension. The results suggest that nonlinear dynamic analysis may be valuable for the analysis of normal and pathological voices but perturbation analysis should be applied with caution for pathological voice analysis.

• 음성과학
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• 제4권2호
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• pp.17-24
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• 1998

In this paper a method to diagnose pathological voices using wavelet transform is sug gested. Pathological voices are collected from hospital and analyzed by the suggested method. Normal voices are collected separately and analyzed. Then the results are compared to find the differences in their characteristics. Three level wavelet transform is used. Normalized energy ratios between the levels and normalized peak-to-peak values are used as parameters. As a result, it was possible to distinguish between normal and pathological voices.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2007년도 한국음성과학회 공동학술대회 발표논문집
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• pp.163-166
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• 2007

Our present study was performed to investigate acoustically the Chines normal adults' voices. 60 Chines normal adults (30 males and 30 females) of the age of 20 to 39 years oridyced systained vowel /a/ and, by analyzing them acoustically with Dr. Speech, we could get the fundamental frequency (Fo), jitter, shimmer, NNE. As results, on the average, male voices showed 1I8.1Hz in Fo, 0.186% in jitter, 1.12% in shimmer, and -13.7dB in NNE. And, female voices showed 252.4Hz in Fo, 0.186% in jitter, 0.81% in shimmer, and -1I.3dB in NNE. Every parameter except Fo showed no significant difference between male and female voices.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.407-408
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• 2007

Robust pitch estimation is an important study in many areas of speech processing. In voice pathology, diverse statistics extracted form pitch were commonly used to test voice quality. In this study, we compared several established pitch detection algorithms (PDAs) for verification of adequacy of the PDAs. In the database of total pathological voices of 99 and normal voices of 30, an analysis of errors related with pitch detection was evaluated between pathological and normal voices, or among the types of pathological voices such as benign vocal fold lesions; polyp, nodule, and cysts. Consequently, it is required to survey the severity of tested voice in order to obtain accurate pitch estimates.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1797-1798
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• 2007

In field of voice pathology, diverse statistics extracted form pitch estimation were commonly used to assess voice quality. In this study, we proposed robust pitch detection algorithm which can estimate pitch of pathological voices in benign vocal fold lesions. we also compared our proposed algorithm with three established pitch detection algorithms; autocorrelation, simplified inverse filtering technique, and nonlinear state-space embedding methods. In the database of total pathological voices of 99 and normal voices of 30, an analysis of errors related with pitch detection was evaluated between pathological and normal voices, or among the types of pathological voices. According to the results of pitch errors, gross pitch error showed some increases in cases of pathological voices; especially excessive increase in PDA based on nonlinear time-series. In an analysis of types of pathological voices classified by aperiodicity and the degree of chaos, the more voice has aperiodic and chaotic, the more growth of pitch errors increased. Consequently, it is required to survey the severity of tested voice in order to obtain accurate pitch estimates.

• 말소리와 음성과학
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• 제2권3호
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• pp.165-170
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• 2010

In this study, the most stable portion was identified using 5% moving window during /a/ sustained phonation in normal and pathologic voice signals and the perturbation values were compared between normal and pathologic voices at the mid-point and at the most stable portion using moving window, respectively. The results revealed that some severe pathologic voice signals can be eligible for perturbation analysis by identifying the most stable portion with Err less than 10. In addition, the perturbation acoustic parameters did not differentiate the pathologic voice signals from the normal voice signals when the mid-point was selected to measure the perturbation analysis(p>0.05). However, significantly higher %shimmer and lower SNR values were observed in pathologic voices (p<0.05) when the most stable portion was selected by moving window. In conclusion, moving window could identify the most stable portion objectively which can allow toget the minimum perturbation values (%jitter, %shimmer) and maximum SNR values. Thus, moving window technique can be applicable for more reliable and accurate perturbation acoustic analysis.

• 말소리와 음성과학
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• 제1권4호
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• pp.147-157
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• 2009

The purpose of the study is to develop the normal voice database and to analyze the acoustic characteristics of Korean adults' voices by gender using MDVP. Eight categories in the 34 parameters of MDVP were analyzed in the voices of 170 Korean normal adults taken from /a/ vowel. Among them, Fundamental Frequency Parameters and Frequency Perturbation Parameters were significantly different by gender. In addition, Fundamental Frequency Parameters of our data were remarkably different from the data suggested in the MDVP program which currently used in clinics. Therefore, the data obtained from the current study can be effectively used for the diagnosis of voice disorders of Korean adults as the standard parameter values of MDVP.

• 음성과학
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• 제9권2호
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• pp.179-192
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• 2002

Our present study was performed to investigate acoustically the Korean normal adults' voices, with enough large number of subjects to be reliable. 120 Korean normal adults (60 males and 60 females) of the age of 20 to 39 years produced sustained three vowels, /a/, /i/, and /u/ and read a part of 'Taking a Walk' paragraph, and by analyzing them acoustically with MDVP of CSL, we could get the fundamental frequency ($F_{0}$), jitter, shimmer and NHR of sustained vowels: speaking fundamental frequency ($SF_{0}$), highest speaking frequency (SFhi), lowest speaking frequency (SFlo) of continuous speech. As results, on the average, male voices showed 118.1$\sim$122.6 Hz in $F_{0}$, 0.467$\sim$0.659% in jitter, 1.538$\sim$2.674% in shimmer, 0.117$\sim$0.114 in NHR, 120.8 Hz in $SF_{0}$, 183.2 Hz in SFhi, 82.6 Hz in SFlo. And, female voices showed 211.6∼220.3 Hz in F0, 0.678∼0.935% in jitter, 1.478∼2.582% in shimmer, 0.098∼0.114 in NHR, 217.1 Hz in $SF_{0}$, 340.9 Hz in SFhi, 136.0 Hz in SFlo. Among the 7 parameters, every parameters except shimmer showed the significant difference between male and female voices. And, when we compared the three vowels, they showed significant differences one another in shimmer and NHR of both genders, but not in $F_{0}$ of males and jitter of females.

• 대한음성학회지:말소리
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• 제62호
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• pp.19-32
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• 2007

This study investigated the perception of emotional voices by transplanting some or all of the prosodic aspects, i.e. pitch, duration, and intensity, of the utterances produced with emotional voices onto those with normal voices and vice versa. Listening evaluation by 24 raters revealed that prosodic effect was greater than segmental & vocal quality effect on the preception of the emotion. The degree of influence of prosody and that of segments & vocal quality varied according to the type of emotion. As for fear, prosodic elements had far greater influence than segmental & vocal quality elements whereas segmental and vocal elements had as much effect as prosody on the perception of happy voices. Different amount of contribution to the perception of emotion was found among prosodic features with the descending order of pitch, duration and intensity. As for the length of the utterances, the perception of emotion was more effective with long utterances than with short utterances.

• 대한음성학회지:말소리
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• 제52호
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• pp.1-14
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• 2004

In this study, we investigated acoustic characteristics of imitated utterances by a professional voice imitator, focusing on prosodic properties such as vowel formants and f0 distribution. To see the patterns of a voice imitation by a professional voice imitator, we compared the imitator's voice data with target speakers' voice data. The professional imitator, Mr. Bae produced utterances imitating the former President Kim's, the comedian Choi's, and the singer Bae's voices. Auditorily, the imitator was judged to imitate all the target speakers' voices successfully. However, acoustic examination showed that the imitator was better at imitating the singer Bae's voice in that the imitator's and the singer Bae's voices are more alike with respect to vowel formants and f0 distribution. We infer this is because the imitator's normal voice is very similar to the singer Bae's voice. On the other hand, the imitator's voice data showed that the patterns of vowel formants and f0 distribution found in the imitator's imitation voices of the other two target speakers were different from those of target speakers' voices.