• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.9 no.1
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• pp.53-58
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• 1998

Objectives : To compare the voice quality and voice problems of untrained professional voice user groups with that of normal control group without voice problem. Materials and Methods : The sustained vowel sounds of 13 male and 36 female teachers, 46 clergies and 15 telephone operators, and 40 normal male and 20 normal female persons were analyzed, using a videostroboscopy and acoustic analyzer. Together with these analyses, a questionnaire associated with risk factors for current and past voice problems was handed over to the patients. Results : The most common symptom in subjective groups was the voice fatigue. In stroboscopic examination, the professional voice user groups shelved functional voice disorder findings regardless of the Intensity of voice use. In the clergy and teacher using loud voice, vocal polyp, vocal nodule and hyperfunction of laryngeal muscle were frequently observed. In the clergy and telephone operator, jitter and shimmer were significantly increased. In the female teacher, the value of jitter, fundamental frequency variation and fundamental frequency were statiscally significant. However, the voice of male teacher showed no significant findings in the acoustic and aerodynamic studies. Conclusion : In the management of voice problems for untrained professional voice user groups, it is important to find the exact causes and patterns of voice problems, and to be individualized the management according to the causes.

• Phonetics and Speech Sciences
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• v.1 no.3
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• pp.133-144
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• 2009

Pharyngeal flap surgery changes the space and shape of the oral cavity and vocal tract, and these changing conditions bring resonance change. The purpose of this study was to determine the most reliable and valuable parameters for evaluating hypernasality to distinguish two patients before and after pharyngeal flap surgery. Each patient was asked to clearly speak the vowels /a/, /i/, /u/, /e/, /o/ for voice recording. There were nine parameters: Formant (F1, F2, F3), Bandwidth (BW1, BW2, BW3), LPC energy slope ($\Delta$ |A2-A1/F2-F1|), and Band Energy (0-500 Hz, 500-1000 Hz) by each vowel. From the results of discrimination analyses on acoustic parameters, the vowels /a/, /e/ appeared to be insignificant but vowels /i/, /u/, /o/ appeared to be efficient in the separation. A 95%, 100%, and 100% recognition score could be reached when vowels /i/, /u/, and /o/ were analyzed. The results showed that F2, BW3, and LPC slope are more important parameters than the others. Finally, there is a relation between perceptual evaluation score and LPC energy slope of acoustic parameters by least square slope.

• Phonetics and Speech Sciences
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• v.6 no.2
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• pp.47-54
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• 2014

The purpose of this study was to analyze spectral versus cepstral measurements in esophageal speakers. The comparison between the measurements in thirteen male esophageal speakers was compared with the control group of thirteen normal speakers using the sustained vowel /a/. The main results can be summarized as below: (a) the CPP and L/H ratio of the esophageal group were significantly lower than those of the control group (b) the CPP was significantly correlated with the spectral parameters such as jitter, shimmer, NHR and VTI, and (c) the ROC analysis showed that the threshold of 10.25dB for the CPP achieved a good classification for esophageal speakers, with 100% perfect sensitivity and specificity. Thus, it was known that cepstral-based acoustic measures such as CPP, may be more reliable predictors than other spectral-based acoustic measures such as jitter and shimmer. And it was found that cepstral-based acoustic measures were effective in distinguishing esophageal voice quality from normal voice quality. This research will contribute to establishing a baseline related to speech characteristics in voice rehabilitation with laryngectomees.

• Journal of Clinical Otolaryngology Head and Neck Surgery
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• v.29 no.2
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• pp.212-222
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• 2018

Background and Objectives : The purpose of this study was to compare the measured values of acoustic and auditory perceptual assessments between normal and functional dysphonia (FD) groups. Materials and Methods : 102 subjects with FD and 59 normal voice groups were participated in this study. Mid-vowel portion of the sustained vowel /a/ and two sentences of 'Sanchaek' were edited, concatenated, and analyzed by Praat script. And then auditory-perceptual (AP) rating was completed by three listeners. Results : The FD group showed higher acoustic voice quality index version 2.02 and version 3.01 (AVQIv2 and AVQIv3), slope, Hammarberg index (HAM), grade (G) and overall severity (OS), values than normal group. Additionally, smoothed cepstral peak prominence in Praat (PraatCPPS), tilt, low-to high spectral band energies (L/H ratio), long-term average spectrum (LTAS) in FD group were lower than normal voice group. And the correlation among measured values ranged from -0.250 to 0.960. In ROC curve analysis, cutoff values of AVQIv2, AVQIv3, PraatCPPS, slope, tilt, L/H ratio, HAM, and LTAS were 3.270, 2.013, 13.838, -22.286, -9.754, 369.043, 27.912, and 34.523, respectively, and the AUC of each analysis was over .890 in AVQIv2, AVQIv3, and PraatCPPS, over 0.731 in HAM, tilt, and slope, over 0.605 in LTAS and L/H ratio. Conclusions : In conclusion, AVQI and CPPS showed the highest predictive power for distinguishing between normal and FD groups. Acoustic analyses and AP rating as noninvasive examination can reinforce the screening capability of FD and help to establish efficient diagnosis and treatment process plan for FD.

• Phonetics and Speech Sciences
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• v.15 no.1
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• pp.25-34
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• 2023

This study examined the utility of the acoustic features of vowels as cues for the place of articulation of Korean nasal consonants. In the acoustic analysis, spectral and temporal parameters were measured at the 25%, 50%, and 75% time points in the vowels neighboring nasal consonants in samples extracted from a spontaneous Korean speech corpus. Using these measurements, linear discriminant analyses were performed and classification accuracies for the nasal place of articulation were estimated. The analyses were applied separately for vowels following and preceding a nasal consonant to compare the effects of progressive and regressive coarticulation in terms of place of articulation. The classification accuracies ranged between approximately 50% and 60%, implying that acoustic measurements of vowel intervals alone are not sufficient to predict or classify the place of articulation of adjacent nasal consonants. However, given that these results were obtained for measurements at the temporal midpoint of vowels, where they are expected to be the least influenced by coarticulation, the present results also suggest the potential of utilizing acoustic measurements of vowels to improve the recognition accuracy of nasal place. Moreover, the classification accuracy for nasal place was higher for vowels preceding the nasal sounds, suggesting the possibility of higher anticipatory coarticulation reflecting the nasal place.

• 재활복지
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• v.18 no.4
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• pp.237-255
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• 2014

Idiopathic Parkinson disease(IPD) is an neurodegenerative disease caused by the loss of dopamine cells in the substantia nigra, a region of midbrain. Its major symptoms are muscular rigidity, bradykinesia, resting tremor, and postural instability. An estimated 70~90% of patients with IPD also have hypokinetic dysarthria. Subthalamic nucleus deep brain stimulation (STN-DBS) has been reported to be successful in relieving the core motor symptoms of IPD in the advanced stages of the disease. However, data on the effects of STN-DBS on speech performance are inconsistent. A medline literature search was done to retrieve articles published from 1987 to 2012. The results were narrowed down to focus on speech performance under STN-DBS based perceptual, acoustic, and/or aerodynamic analyses. Among the 32 publications which dealt with speech performance after STN-DBS indicated improvement(42%), deterioration(29%), mixed results(26%), or no change(3%). The most favorite method was found to be based upon acoustic analysis by using a vowel prolongation and Unified Parkinson's Disease Rating Scale(UPDRS). For the purpose of verifying the effect of the STN-DBS, speech evaluation should be undertaken on all speech components such as articulation, resonance, phonation, respiration, and prosody by using a contextual speech task.

• Phonetics and Speech Sciences
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• v.14 no.1
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• pp.21-28
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• 2022

Previous studies have provided important findings on children's speech production development. They have revealed that essentially all aspects of children's speech shift toward adult-like characteristics over time. Nevertheless, few studies have examined the perceptual aspects of children's speech tokens, as perceived by naive adult listeners. To fill the gap between children's production and adults' perception, we conducted cross-sectional perceptual studies of monosyllabic words produced by children aged two to six years. Monosyllabic words in the consonant-vowel-consonant form were extracted from children's speech samples and presented aurally to five listener groups (20 listeners in total). Generally, the agreement rate between children's production of target words and adult listeners' responses increases with age. The perceptual responses to tokens produced by two-year old children induced the largest discrepancies and the responses to words produced by six years olds agreed the most. Further analyses were conducted to identify the sources of disagreement, including the types of segments and syllable structure. This study makes an important contribution to our understanding of the development and perception of children's speech across age groups.