• Speech Sciences
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• v.15 no.2
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• pp.177-189
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• 2008

This study was to investigate diadochokinetic (DDK) rate, regularity and mean flow rate of articulation valves in dysarthria. DDK rate, mean airflow rate (MFR) and regularity of DDK syllable repetitions of vocal function /ihi/, tongue function /ta/, velopharyngeal function /bm/, and labial function /pa/ in 24 normal and dysarthric speakers were measured. Aerophone Ⅱ and Motor Speech Profile were used for data recording and analysis. The results of the findings were as follows: First, there were significant differences between the dysarthria and the normal group in DDK rate. DDK rates in ataxic dysarthria were the lowest and spastic, flaccid, and hypokinetic dysarthria followed in sequence. Second, there was a significant difference between the dysarthria and the normal group in DDK regularity. Third, there was a significant difference between dysarthria groups and normal group in DDK MFR. Finally, there was a significant difference between the 4 groups of dysarthria and the normal group in DDK air flow tracking. The results of this study can be guidelines for normal DDK rate, regularity and flow rate in dysarthria groups. In addition, their differential diagnoses and descriptions are important to make a decision on medical and behavioral management of the individuals with disorders according to DDK characteristics.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.185-192
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• 2010

The acoustic vowel space has been used as an acoustic parameter in dysarthric speech. The aim of this work was to examine mathematical formulae for acoustic vowel space and to apply these to Korean speakers with idiopathic Parkinson's disease(IPD). Five acoustic parameters were chosen from earlier works and one new parameter was proposed, the pentagonal vowel space. The six parameters included triangular vowel space (3 area), irregular quadrilateral vowel space (4 area), irregular pentagonal vowel space (5 area), vowel articulatory index (VAI), formant centralization ratio (FCR) and F2i/F1u ratio (F2 ratio). An experimental group of 32 IPD patients(male:female=16:16) and a control group of twenty healthy people (male:female=8:12) participated in the study and repeated vowels (/a-i-u-e-o/) three times. A correlation analysis was performed among the six parameters, 2-way ANOVA was done with gender and groups as independent factors, and an independent sample t-test was conducted between the male and the female group as post hoc comparison. All parameters were highly correlated with each other and only the FCR showed a high negative correlation with the others. The results of ANOVA showed a significant difference in F2 ratio, 3 area, 4 area and 5 area between gender and in 4 area and 5 area between groups. For the male members of the two groups, significant statistical differences were found in all parameters whereas no such differences were found for the female members. These findings indicated that the vowel space of the female group was wider than the vowel space of the male group. These differences may have been caused by gender-specific speech styles rather than by patho-physiological mechanisms. We also claim that the pentagonal vowel space is better than the other vowel spaces at representing the disordered speech in natural speech situations.

• Phonetics and Speech Sciences
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• v.13 no.2
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• pp.57-66
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• 2021

This study focuses on the issue of automatic severity classification of dysarthric speakers based on speech intelligibility. Speech intelligibility is a complex measure that is affected by the features of multiple speech dimensions. However, most previous studies are restricted to using features from a single speech dimension. To effectively capture the characteristics of the speech disorder, we extracted features of multiple speech dimensions: voice quality, prosody, and pronunciation. Voice quality consists of jitter, shimmer, Harmonic to Noise Ratio (HNR), number of voice breaks, and degree of voice breaks. Prosody includes speech rate (total duration, speech duration, speaking rate, articulation rate), pitch (F0 mean/std/min/max/med/25quartile/75 quartile), and rhythm (%V, deltas, Varcos, rPVIs, nPVIs). Pronunciation contains Percentage of Correct Phonemes (Percentage of Correct Consonants/Vowels/Total phonemes) and degree of vowel distortion (Vowel Space Area, Formant Centralized Ratio, Vowel Articulatory Index, F2-Ratio). Experiments were conducted using various feature combinations. The experimental results indicate that using features from all three speech dimensions gives the best result, with a 80.15 F1-score, compared to using features from just one or two speech dimensions. The result implies voice quality, prosody, and pronunciation features should all be considered in automatic severity classification of dysarthria.

• MALSORI
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• no.48
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• pp.1-17
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• 2003

Among the types of dysarthria, spastic and flaccid types are the most prominent manifestations. The objectives of the present research are (1) to discover the phonetic contrasts that differentiate spastic dysarthria from flaccid dysarthria, (2) to analyze the degrees of predictability of each phonetic contrast for intelligibility in spastic and flaccid dysarthrias and to compare them. The 'phonemic contrast word intelligibility pairs' for dysarthric speakers were tested and proved to be useful for clinical assessment of and research on dysarthria. In the group of spastic type, it showed that initial fricative vs. affricate and front vs. back vowel contrasts are transmitted relatively less effectively than flaccid type. In the group of flaccid type, initial glottal vs null contrast is transmitted less effectively than spastic type. The overall intelligibility of spastic dysarthria was predicted by multiple regression analysis with 88% accuracy by three phonetic contrasts(initial fricative vs. affricate; front vs. back vowels; initial consonant correlates). And the intelligibility of flaccid dysarthria was predicted by two phonetic contrasts(initial nasal vs. stop, front vs. back vowels) with 60% accuracy.

• Therapeutic Science for Rehabilitation
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• v.9 no.1
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• pp.91-99
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• 2020

Objective : The purpose of this study was to investigate the effects of the IOPI articulator strength training program on articulator(tongue and lip) muscle strength, numbers of /l, s, ʨ/ articulation accuracy, articulatory numbers, articulation regularity and accuracy in the alternate motion rates, and sequential motion rate changes in patients with spastic dysarthria. Methods : Three cases of patients with spastic dysarthria living in Jeju, Korea, were included in this study. A single subject design was selected to study changes in articulator(tongue and lip) muscle strength, numbers of /ㄹ, ㅅ, ㅈ/ articulation accuracy, articulatory numbers, articulation regularity and accuracy in the alternate motion rates and sequential motion rates. Results : After the articulator strength training program was conducted on patients with spastic dysarthria, there were positive changes in articulator(tongue and lip) muscle strength, numbers of /ㄹ, ㅅ, ㅈ/ articulation accuracy, articulatory numbers, articulation regularity and accuracy on the alternate motion rates and sequential motion rates. Conclusion : Our findings suggest that IOPI articulator strength training program could be very useful for the most representative childeren with cerebral palsy if conducted in various subtypes of dysarthric patients and linked with articulatory function training with IOPI at home.