• Neonatal Medicine
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• v.18 no.2
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• pp.328-336
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• 2011

Purpose: An association between very low birth weight infants(VLBWI) and hearing loss has long been recognized. Early identification and intervention for hearing loss benefits language and speech/cognitive development. We investigated the risk factors and clinical outcomes of hearing loss among VLBWI. Methods: We analyzed the results of auditory brainstem response (ABR) testing of VLBWI. These infants were admitted to the neonatal intensive care unit (NICU) of Pusan National University Yangsan Hospital between December 2008 and February 2011. A follow-up was conducted subsequently. Results: ABR evaluations were performed on 65 infants, and 31 showed abnormal results (47.7%). Among the 31 infants, 10 were classified with moderate/severe/profound hearing loss (15.4%). The infants with abnormal ABR had a higher incidence of low birth weight, prolonged ventilator care, cumulative dose of furosemide, and the lowest $PaO_2$ (P<0.05). Those with moderate/severe/profound hearing loss had a higher incidence of low Apgar scores at 5 minutes (odds ratio[OR],0.34; 95% confidence interval[CI],0.13-0.89), prolonged ventilator care (OR,1.06; 95% CI,1.01-1.12), and mild hearing loss compared to those without profound hearing loss. Follow-up evaluations on eight infants with ABR reveled improvements 5.6${\pm}$3.9 months later. One infant, who had profound hearing loss in both ears, used a hearing aid. Conclusion: Factors influencing hearing loss at the first VLBWI hearing screening test included lower Apgar scores at 5 min and prolonged use of a ventilator. Most VLBWI with hearing losses were expected to recover after several months of follow-up.

• Clinical and Experimental Pediatrics
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• v.49 no.8
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• pp.845-850
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• 2006

Purpose : To assess the incidence of neonatal hearing loss in a neonatal intensive care unit and the relative importance of risk factors for hearing imparement in a neonatal intensive care unit which the Joint Committee on Infant Hearing(JCIH) had recommended. Methods : One thousand, two hundred and one newborns admitted to the Good Moonhwa Intensive Care Unit from May 2003 to December 2005 were assesed using the automated auditory brainstem response(AABR). The screening was performed on those aged more than 36 weeks and weighing more than 2,200 g. We divided the infants into two groups, 'pass' and 'refer'. The 'refer' group were retested one month later, and if classified as 'refer' during the retest, were referred to a hearing impairment clinic. Results : From the 1,201 neonates, 1,187(98.8 percent) passed the test and 14(1.2 percent) failed. 293(24.4 percent) of the 1,201 neonates had a risk factor for hearing impairment; 282(96.2 percent) passed the test and 11(3.8 percent) failed. The group with risk factors were shown to have a higher incidence of hearing loss(P<0.001). The neonates in the refer group were shown to have a higher incidence of ototoxic drugs(P<0.001), low birth weight(<1,500 g)(P<0.001) and craniofacial anomalies(P=0.007). On the other hand, there were no statistical differences between the pass and refer groups in congenital infection, hyperbilirubinemia, bacterial meningitis, low Apgar scores, prolonged mechanical ventilation and syndromes known to include hearing loss. Conclusion : In order to identify hearing-impaired infants within an appropriate period, neonatal hearing screening tests and identification of the risk factors for neonatal hearing loss are important.

• 대한예방의학회:학술대회논문집
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• 2005.10a
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• pp.372-372
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• 2005

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1990.10a
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• pp.47-50
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• 1990

종래에는 공조덕트의 소음 감소를 위하여 주로 흡음재료를 사용하여 왔다. 그러나 이러한 흡음재료를 이용한 소음감소대책은 500HZ 이상의 고주파 영 역에서는 효과가 있으나 500HZ 이하의 저주파 영역에서는 효과가 적다. 이 러한 500HZ이하의 저주파 소음은 각종 구조물의 진동을 야기시켜 정밀작업 이 요구되는 작업환경을 파괴하고, 심지어는 구조물에 손상을 입힐수도 있 다. 또한 이러한 저주파 소음에 노출된 사람의 심리를 불안하게 하여 일의 효율을 떨어뜨릴 뿐만 아니라 청력장애를 일으키기도 한다. 또한 청정환경이 요구되는 곳에서의 소음감소를 위하여 흡음재료를 사용할 경우 흡음재료로 부터 떨어져 나오는 미세분에 의해 청정환경의 보존이 어려워진다. 이러한 흡음재료를 이용한 수동소음제어 대책의 단점을 해결하기 위하여 소음을 그 소음과 동일한 진폭을 갖으며 위상차가 180도인 인위적인 음파로 상쇠시키 는 능동소음제어대책의 개발이 요구되어 왔다. 본 논문은 덕트 또는 이와 유 사한 음향환경내에서의 적응필터기법(adaptive filtering technique)을 이용한 능동소음제어방법의 개발, 실제구현 및 성능평가에 관한 것으로서, 특히 다 수의 에러 마이크로폰과 다수의 소음제어용 스피커를 사용하여 제어계통의 가관측성(Observability)및 가제어성(Controllability)을 향상시켜 평면파로 전 달되는 소음의 감소를 증대시킬수 있을 뿐만 아니라 고차모드(Higher-order mode)로 전달되는 소음의 제어도 가능케하는 능동소음제어 방법에 관하여 논하였다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.2
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• pp.205-212
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• 2016

In this paper, we implement the development platform of multichannel digital hearing aid algorithm using Simulink provided by Matlab. The digital hearing aids are considered medical devices designed to compensate for hearing loss, they need to be correctly selected, to help a person who has difficulty in hearing. The development platform that implemented in this paper, includes WOLA filterbank for analysis/synthesis of input signal, Wide dynamic range compression for hearing loss compensation and adaptive filter for feedback cancellation. Using the development platform, algorithm parameters for each block can be set depending on the hearing aid user. Thus it is possible to test the algorithm before the machine language. As a result, the time for algorithm development can be saved and performance and computational complexity can be optimized.

• Journal of Biomedical Engineering Research
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• v.20 no.4
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• pp.495-502
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• 1999

We propose efficient speech signal processing algorithms and a system for cochlear implant in this paper. The outer and the middle car which perform amplifying, lowpass filtering and AGC, are modeled by an analog system, and the inner ear acting as a time-delayed multi filter and the transducer is implemented by the DSP circuit which enables real-time processing. Especially, the basilar membrane characteristic of the inner ear is modeled by a nonlinear filter bank, and then tonotopy and periodicity of the auditory system is satisfied by using a pitch-synchronous multi-spectra(PSMS) method. Moreover, most of the speech processing is performed by S/W so the system can be easily modified. And as our program is written in C-language, it can be easily transplanted to the system using other processors.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.203-206
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• 1997

본 연구는 G7 의료공학기술개발사업의 1차년도 연구결과이다. 본 연구의 최종목표는 청각계통중 내이의 손상에 의한 감각성 난청환자에게 소리를 인식할 수 있게 하는 한국형 인공와우의 개발, 전 음성 난청환자의 음성인식 효율을 높일 수 있는 한국형 인공이소골의 개발 그리고 인공와우 시술환자에게 적합한 재활용 프로그램을 개발하는데 있다. 이를 위하여 지난 1차년도에는 코클리어의 전기생리학적 현상을 규명하고, 이식전극시스템과 그 주변장치를 설계, 평가하였다. 그리고 한국인의 성인사체의 16귀를 측정하여 한국인 체형에 적합한 인공이소골의 설계기준을 확립하였다. 또한, 인공와우 시술 후 청력회복에 필요한 한국형 재활프로그램의 개발을 위하여 인공와우의 coding strategy에 따른 언어분별력 조사, 유소아의 어음특성분석등을 행하였다. 이 연구결과를 토대로 차기년도에는 상용화에 근접한 프로토타잎의 제품개발과 임상실험이 진행되리라 생각된다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.19 no.1
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• pp.20-28
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• 1982

This is a preliminary animal experiment for development of the electronic ears for deaf patients. In 10 Guinea Pigs'ears, we have measured the changes of cochlear microphonics (CM) for Pure sound after application of 100dB white noise sound and NaCl crystal. In response to white noise sound, the amplitude of cochlear microphonics for pure sound has decreased by 30% in 30 minutes, then it has recovered to its initial control amplitude in 90minutes. In NaCl crystal application, the amplitude of cochlear microphonics for pure sound has decriased by 50% in 15minutes and has remained at reduced level. Also, the deaf Guinea Pig shows a motion reflex for sound when we apply electrical signals similar to cochlear microphonics to the electrodes located in the round window of the inner ear.

• The Journal of Korean Academy of Sensory Integration
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• v.7 no.1
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• pp.59-69
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• 2009

Objective : The purpose of the study is to examine the length of institutionalization and sensory modulation for preschooler without disabilities, and to investigate the relationship between the length of institutionalization and behavioral problem. Method : Mothers of preschoolers without disabilities between ages of 3 and 7 who attend D kindergarten was participated. Nursery school teacher of institutionalized children without disabilities between ages of 3 and 7 who attend child-welfare facilities was participated. We used Short Sensory Profile(SSP) and Children Behavior Check list. The results were analyzed with SPSS 11.0. Results : There was no significant difference between longer length of institutionalization and shorter length of institutionalization in sensory modulation and behavioral problem. Regarding the sensory modulation and behavior problem according to child-welfare facilities, means showed the statistically significant difference. Regarding sensory modulation of test items, movement sensitivity and low energy/weak showed the statistically significant difference in home-reared children than institutionalized children. Conclusions : The results of the study showed high correlation environmental effect in institutionalized children. Further research is needed to improve environmental for institutionalized children.

• 재활복지
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• v.22 no.4
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• pp.103-121
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• 2018

For knowing the effects of aging on conversational skills in daily communication, this paper studied for the conversational turn-taking skills, working memory and naming ability on healthy elderly adults over 65 ages. 85 elderly adults participated in this study, which divided into four groups by ages. Speech samples were collected in natural conversation. Memorization of numbers, mental calculation, repetition of words were administered for working memory test. K-BNT was used for the naming ability. One-way ANOVA analysis was used for the comparison of conversational turn-taking skills among four groups. We analyzed the correlation between conversational skills, working memory and naming ability. The results were as follows: first, there were a significant difference in conversational turn-taking skills by age, but not by gender. There was a significant difference in 'Turn-Taking Frequency' and 'Total Utterance Frequency' among four groups. The same results were shown in the scores of females within three groups(exclude groups over 85D)(p<.01). Second, there was a significant correlation between 'rates of maintenance' and 'naming ability'. In addition, it was found that the naming test predicted 'rates of maintenance' skills. The results of this study suggest that word-retrieval ability will be helpful to enhance functional communication skills in aging old adults.