• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.6
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• pp.509-523
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• 2012

The sound quality based on design optimization, throughout the development process of various electronic office equipments, needs to be considered in order to respond the increased needs for the emotional satisfaction of customers in terms of psycho-acoustics. This paper focuses on how to describe the characteristics of operating sound radiated from laser printers by using various sound attributes, and to model the sound quality index that can properly evaluate the subjective preference on modification conditions in the improvement study quantitatively. Especially, the proposed verification process, in the form of combining the correlation based method and the decision error based method, was applied to improve the generality and reliability of a group of participants in the jury evaluation. The modified Aures tonality model was also proposed to improve the correlation coefficient with the mean response of participants by optimizing some parameters. As a result, the loudness, articulation index, roughness, tonality, fluctuation strength were used to model the sound quality index for laser printers by using the multiple-linear regression method. Through the improvement study, it was confirmed that replacing the absorbing materials is effective to reduce the tonalness radiated from the side of a reference printer model. Based on above results, it can be concluded that the proposed model has enough usefulness as quantitative evaluation index to evaluate the difference between modification conditions in the improvement study.

• Clinical and Experimental Pediatrics
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• v.50 no.9
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• pp.896-900
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• 2007

Purpose : The aim of this study was to investigate the speech problems in benign rolandic epilepsy (BRE) according to the seizure focus in EEG and semiology. Methods : Twenty three patients [right origin (13 patients) or left side (10 patients)] who met the BRE criteria by International League Against Epilepsy (ILAE) were prospectively enrolled. We excluded the patients who had abnormal MRI or showed both side spikes in EEG. Computerized Speech Lab was used to assess the speech characteristics of the patients. Results : The error pattern of laryngeal articulation in BRE was exclusively substitution of stop consonants, these errors showed more frequent in the left group (16.0% vs 25.5%). Voice onset time (VOT) of stop consonants and Total duration (TD) of word in both groups were prolonged than normal control group, especially in left group (P<0.05). The first formant of vowel /o/ and second formant of /e/ were significantly decreased in left group (P<0.05). The right group scored wider on pitch range ($192.9{\pm}54.0Hz$) and energy range in spontaneous speech ($14.2{\pm}6.4db$) than the left group ($233.3{\pm}12.5Hz$, $19.4{\pm}9.3db$, respectively, P>0.05). Duration of counting (5 to 9) in left group slower than right group ($8.6{\pm}1.7$ vs $7.9{\pm}1.8sec$). Conclusion : Our data suggested that interictal spikes and seizures in either centrotemporal sides, especially left side group, may induce speech problems. We recommend the logopedic and phoniatric evaluations of speech in BRE patients.

• 한국노년학
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• v.32 no.3
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• pp.747-758
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• 2012

Detecting probable Alzheimer's disease (AD) at an early stage is crucial in slowing the progression of the disease and initiating drug therapy for more effective symptom management. Therefore, this study aimed to identify linguistic features that allow us to distinguish between patients with AD and normal controls. This paper reports on characteristics of spontaneous speech in subjects in three stages of AD (questionable, mild, moderate) compared with education- and age-matched normal controls. Four components of speech were measured in Korean native speakers with AD and normal aging: speech tempo, hesitation (measured in seconds), rate of articulation errors, and rate of grammatical errors. The results revealed significant differences in most of these speech components among the four groups, including significant differences between normal controls and the questionable AD group in the areas of speech tempo and rate of grammatical errors. Phonological? articulatory ability was preserved in questionable AD, and grammatical ability was preserved in questionable and mild AD. Subjects with moderate AD were severely impaired in grammatical ability. Prospective assessments of spontaneous speech skills using a dialogue and picture-description task are useful in detecting the subtle, spontaneous speech impairments that AD causes even in its early stage.

• Therapeutic Science for Rehabilitation
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• v.8 no.2
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• pp.67-78
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• 2019

Objective : The purpose of this study was to investigate the effect of hand tapping on the accuracy and the fluency of speech production in children with speech sound disorder(SSD) and their typically developing peers(TD). Methods : The study subjects were 15 SSD children and 15 TD children aged 4, 5, and 6 years of age. Subjects were asked to give a picture name without hand tapping in the first experimental condition, and with hand tapping in the second experiment condition. Results : The results showed that hand tapping significantly increased disfluency in TD, whereas in SSD. it did not affect the accuracy or fluency of speech production. In addition, TD demonstrated a significant positive correlation with the changes of accuracy and disfluency due to hand tapping, whereas SSD had no correlation. Conclusion : We discussed the possibility that hand tapping could serve as an obstacle distracting attention from SSD and TD, acting as a motor gesture to facilitate phonological processing when facing the difficulty in lexical retrieval for SSD.