• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.26 no.2
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• pp.117-121
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• 2015

Background : Cepstral analysis which is obtained from Fourier transformation of spectrum has been known to be effective indicator to analyze the voice disorder. To evaluate the voice disorder, phonation of sustained vowel /a/ sound or continuous speech have been used but the former was limited to capture hoarseness properly. This study is aimed to compare the effectiveness in analysis of cepstrum between the sustained vowel /a/ sound and continuous speech. Methods : From March 2012 to December 2014, total 72 patients was enrolled in this study, including 24 unilateral vocal cord palsy, vocal nodule and vocal polyp patients, respectively. The entire patient evaluated their voice quality by VHI (Voice Handicap Index) before and after treatment. Phonation of sustained vowel /a/ sample and continuous speech using the first sentence of autumn paragraph was subjected by cepstral analysis and compare the pre-treatment group and post-treatment group. Results : The measured values of pre and post treatment in CPP-a (cepstral peak prominence in /a/ vowel sound) was 13.80, 13.91 in vocal cord palsy, 16.62, 17.99 in vocal cord nodule, 14.19, 18.50 in vocal cord polyp respectively. Values of CPP-s (cepstral peak prominence in text-based speech) in pre and post treatment was 11.11, 12.09 in vocal cord palsy, 12.11, 14.09 in vocal cord nodule, 12.63, 14.17 in vocal cord polyp. All 72 patients showed subjective improvement in VHI after treatment. CPP-a showed statistical improvement only in vocal polyp group, but CPP-s showed statistical improvement in all three groups (p<0.05). Conclusion : In analysis of cepstrum, text-based analysis is more representative in voice disorder than vowel sound speech. So when the acoustic analysis of voice by cepstrum, both phonation of sustained vowel /a/ sound and text based speech should be performed to obtain more accurate result.

• Phonetics and Speech Sciences
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• v.10 no.3
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• pp.49-59
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• 2018

The purpose of this study was to investigate vocal hygiene habits and Korean Voice-Related Quality of Life (K-VRQOL) among classical singers. A total of 128 classical singers filled an online voice and K-VRQOL questionnaire, and the results were analyzed. In order to investigate the characteristics of K-VRQOL according to age groups, and the presence or absence of a history of voice problems, we conducted a two-way ANOVA. The results are as follows. Of the 128 classical singers, 28 (21.9%) with a history of voice problems said that excessive conversation, singing practice, and yelling were the causes of their voice problems. The symptoms of voice problems were fatigue, loss of range, hoarseness, and breathiness. In addition, classical singers were less likely to smoke, or to drink alcohol or caffeine. The K-VRQOL was highly correlated with all sub-domains. There was a statistically significant difference according to age groups (p<.05) and history of voice problems (p<.01). There was no correlation between age groups and history of voice problems. Voice management is important because classical singers can ruin their voice by speaking, and the risk of voice disorder is high. Voice problems affect quality of life. In future studies, it is necessary to obtain information on the subjective voice characteristics of classical singers by examining the relationship between their voice hygiene habits and VHI, SVHI, and K-VRQOL.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.30 no.2
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• pp.87-94
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• 2019

The purpose of this study was to investigate the speech characteristics and speech therapy of Parkinson disease (PD). This study selected 28 papers published in Korea from 1998 to 2018 after searching the terms 'Parkinson voice' and 'Parkinson speech therapy.' Literature review had been conducted in the two aspects of speech characteristics and speech therapy. The speech characteristics were divided into respiration, phonation, articulation, prosody, vowel production, and voice questionnaire. Speech therapy was divided into Lee Sliverman voice treatment (LSVT) and other voice therapy. PD patients did not differ in respiration function compared to normal elderly people, but their speech and articulation function were poorer. There was also a difference in the speech rate, frequency of pause, and accuracy of vowel production compared with normal elderly people. PD had a lower VHI score and their voice related quality of life was a little poorer. The LSVT was typically used in speech therapy for PD. The methods of speech therapy for PD have been shown to improve respiration and phonation. It is necessary to establish voice norms in PD patients and develop effective speech therapy in the following study.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.6
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• pp.121-131
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• 2018

Climate change has caused changes in environmental factors that have a direct impact on agriculture such as temperature and precipitation. The meteorological disaster that has the greatest impact on agriculture is drought, and its forecasts are closely related to agricultural production and water supply. In the case of terrestrial data, the accuracy of the spatial map obtained by interpolating the each point data is lowered because it is based on the point observation. Therefore, acquisition of various meteorological data through satellite imagery can complement this terrestrial based drought monitoring. In this study, Evaporative Stress Index (ESI) was used as satellite data for drought determination. The ESI was developed by NASA and USDA, and is calculated through thermal observations of GOES satellites, MODIS, Landsat 5, 7 and 8. We will identify the difference between ESI and other satellite-based drought assessment indices (Vegetation Health Index, VHI, Leaf Area Index, LAI, Enhanced Vegetation Index, EVI), and use it to analyze the drought in South Korea, and examines the applicability of ESI as a new indicator of agricultural drought monitoring.

• Phonetics and Speech Sciences
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• v.4 no.4
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• pp.95-107
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• 2012

As BTX-A, which has been known to be the most effective treatment for ADSD, is not effective in treating vocal tremors, voice assessment must be employed to perform differential diagnosis of SD and vocal tremor in an accurate fashion. In this study, the characteristics of vocal changes after botulinum toxin injection were compared by analyzing the voice characteristics resulting from the presence of vocal tremors using objective analysis devices, with the aim of helping to provide prognoses and to determine remedial effects in clinical cases comprising patients with adductor spasmodic dysphonia accompanied by voice tremors. Respiratory function tests, aerodynamic analysis, electroglottography (EGG), acoustic analysis, auditory perception tests, and K-VHI had been conducted at intervals of four, eight, and twelve weeks before and after injection, targeting a group of 17 ADSD female patients (a ADSD group of four with vocal tremor and a ADSD group of 13 without voice tremor). For average FVC and FEV1, the T group showed statistically significant low averages compared with the NT group, whereas the T group showed statistically significant high average ATRI compared with the NT group. In addition, the T group showed a statistically significant Fatr, lower than that of the NT group. For the ADSD group of patients with voice tremor, their vocal tremor remained unchanged despite noticeable decrease in wringing voices. In other words, as the vocal tremor and wringing voices are two distinctive features, there is a need for the two features to be targeted separately for differential diagnosis.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.75-82
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• 2010

Many previous studies based on respiratory characteristics of Idiopathic Parkinson's Diseases (IPD) patients have not controlled related factors appropriately. Accordingly, these studies produced discordant results. Furthermore, there is currently a lack of studies that can provide precise explanations on the characteristics of respiration and phonation. This study included a total of 40 subjects: 20 mixed gender de novo IPD patients ranging in age from 50 to 80 (Hoehn & Yahr stage 1~3), and 20 normal subjects with similar matches for age and gender. All participants were controlled based on their gender, age, height, weight, vocal fold function, cognitive abilities, and depression factors. K-MMSE (Korean-Mini Mental State Examination), nVHI-10 (new Voice Handicap Index), and KGDS (Korean Form of Geriatric Depression Scale) were evaluated to select this study subjects. In order to compare respiratory functions between the two groups, FVC, FEV1, and FEV1/FVC were measured using microQuark, a PC-based spirometer. CSL was used by measure MPT and PAS was used to measure MFR. To investigate the characteristics of phonation ability, CSL was used to measure jitter and shimmer, while PAS was used to measure Psub. In order to compare the respiratory function averages and phonation ability between the two groups, statistical analysis was conducted using SPSS (version 12.0). The results of this study showed that most de novo IPD patients were included in the normal average range of respiratory and phonatory ability. But the respiratory and phonatory ability of de novo IPD patients showed lower tendency as compared with the normal group. When the average of respiratory and phonatory ability among the gender was compared, the difference of males was greater than the difference of females.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.27 no.2
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• pp.108-113
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• 2016

Background and Objectives : After thyroidectomy, many patients experience problems report such things as reduced voice range and vocal fatigue, swallowing problems without superior and recurrent laryngeal nerve injury. The purpose of this study was to evaluate voice and swallowing problems before and after thyroid surgery without laryngeal nerve injury. Materials and Methods : Ninety-three patients who underwent thyroidectomy without laryngeal nerve injury and completed the follow-up evaluations were studied between June 2013 and December 2015. Each evaluation was performed preoperatively, as well as 1 week, 1 month postoperatively. Analysis was performed including voice handicap index (VHI), dysphagia handicap index (DHI), and acoustic voice analysis. Results : Patients show significant variation of parameters in the fundamental frequency (F), maximal phonation time (MPT), shimmer, jitter and soft phonation index (SPI) early after operation, and most of them showed recovery of parameters after 1month of operation. Perceptive complaint of voice and swallowing also showed significant decreased after operation (p<0.005). After 1month of operation, MPT, highest frequency and frequency ranges still showed significant decreased parameters. Comparing acoustic and perceptive parameters of total thyroidectomy and lobectomy, there was no significant changes between them except highest frequency (p=0.042). Conclusion : The results from both subjective and objective evaluations show voice and swallowing disturbance after thyroidectomy even in the absence of laryngeal nerve and provide patients information about the recovery process after surgery. Highest frequency parameter showed most significant changes after operation.

• Investigative Magnetic Resonance Imaging
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• v.16 no.2
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• pp.136-141
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• 2012

Purpose : To investigate the pharmacologic modulation of motor task-dependent physiologic responses by antiplatelet agent, clopidogrel, during hand motor tasks in healthy subjects. Materials and Methods: Ten healthy, right-handed subjects underwent three functional magnetic resonance (fMRI) sessions: one before drug administration, one after high dose drug administration and one after reaching drug steady state. For the motor task fMRI, finger flexion-extension movements were performed. Blood oxygenation level dependent (BOLD) contrast was collected for each subject using a 3.0 T VHi (GE Healthcare, Milwaukee, USA) scanner. $T2^*$-weighted echo planar imaging was used for fMRI acquisition. The fMRI data processing and statistical analyses were carried out using SPM2. Results: Second-level analysis revealed significant increases in the extent of activation in the contralateral motor cortex including primary motor area (M1) after drug administration. The number of activated voxels in motor cortex was 173 without drug administration and the number increased to 1049 for high dose condition and 673 for steady-state condition respectively. However, there was no significant difference in the magnitude of BOLD signal change in terms of peak T value. Conclusion: The current results suggest that cerebral motor activity can be modulated by clopidogrel in healthy subjects and that fMRI is highly senstive to evidence such changes.