• Investigative Magnetic Resonance Imaging
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• v.9 no.2
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• pp.134-139
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• 2005

Purpose : To evaluate the usefulness of acoustic noise attenuator on auditory fMRI examination. Materials and methods : The acoustic noise attenuator consists of mask, earmuff and silicon earplug. The soft polyurethane sheet and polyurethane form , which has a good soundproof characteristic were used for mask and earmuff. Auditory fMRI experiments of 500 Hz pure tone stimulation were performed in three different cases; first all of mask, earmuff and earplug, secondly earmuff and earplug only and finally without attenuator in 4 normal hearing volunteers. For data acquisition, BOLD MR imaging technique was employed at a 1.5T MR scanner equipped with high performance gradient system. The raw data were analyzed using a SPM-99 analysis software and the activation maps were obtained. Results : In case of all items of acoustic attenuator used, the results revealed that activation was focused on primary auditory area. When only earmuff and earplug were used, the results showed that the activation spread over primary auditory and secondary associative areas. Last, when no device used, only weak activation was observed on the right auditory cortex. Conclusion : It is expected that the acoustic noise attenuator, which consists of earplugs, earmuffs and mask, is a very useful device in auditory fMRI study.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.4
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• pp.314-321
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• 2000

In order to obtain the fundamental data on the auditory thresholds of fishes for catching method using low frequency sound, the auditory thresholds of coralfish Chromis notatus were measured in the presence of masking noise in the spectrum level range of 73~83dB re l$\mu$Pa/√Hz by heartbeat conditioning technique using pure tones coupled with a delayed electric shock. Critical ratios were about 23~41dB at measurement frequency, The critical ratio increased almost linearly with increasing frequency from 500Hz. The noise spectrum level at the start of masking was about 60~65dB. This suggests that hearing of coralfish is masked in the natural environment with the noise spectrum level above 60dB. The sound pressure level of which the signal sound of 300Hz is recognized by coralfish under the ambient noise is above 88dB and the critical ratio of them is above 23dB. The hearing index of coralfish with ambient noise was 81.

• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.369-376
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• 2004

The tinnitus retraining therapy(TRT) is an effective method for treating tinnitus patients. This therapy use the white noise to stimulate auditory cells for a wide frequency range. In this paper, the small white noise generator using the thermal noise is proposed. And frequency response controller which can compensate the frequency response changed by the human outer and middle ear system is proposed. We can know that proposed system is more proper type on a purpose of the tinnitus retraining therapy comparing with conventional white noise generator.

• The Journal of the Acoustical Society of Korea
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• v.35 no.1
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• pp.63-73
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• 2016

It is widely acknowledged that the human auditory system is organized tonotopically and people generally listen to sounds as a function of frequency distribution through the auditory system. However, it is still unclear how acoustic features of speech sounds are indicated to the human brain in terms of speech perception. Thus, the purpose of this study is to investigate whether two sounds with similar high-frequency characteristics in the acoustic analysis show similar results at the level of auditory brainstem. Thirty three young adults with normal hearing participated in the study. As stimuli, two Korean monosyllables (i.e., /ja/ and /cha/) and four frequencies of toneburst (i.e., 500, 1000, 2000, and 4000 Hz) were used to elicit the auditory brainstem response (ABR). Measures of monosyllable and toneburst were highly replicable and the wave V of waveform was detectable in all subjects. In the results of Pearson correlation analysis, the /ja/ syllable had a high correlation with 4000 Hz of toneburst which means that its acoustic characteristics (i.e., 3671~5384 Hz) showed the same results in the brainstem. However, the /cha/ syllable had a high correlation with 1000 and 2000 Hz of toneburst although it has acoustical distribution of 3362~5412 Hz. We concluded that there was disagreement between acoustic features and physiology outcomes at the auditory brainstem level. This finding suggests that an acoustical-perceptual mapping study is needed to scrutinize human speech perception.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.12
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• pp.2349-2356
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• 2008

In this paper, we present the method to effectively extract and classify the EEG caused by only brain activity when a normal subject is in a state of mental activity. We measure the synchronous EEG on the auditory event when a subject who is in a normal state thinks of a specific task, and then shift the baseline and reduce the effect of biological artifacts on the measured EEG. Finally we extract only the mental task signal by averaging method, and then perform the recognition of the extracted mental task signal by computing the AR coefficients. In the experiment, the auditory stimulus is used as an event and the EEG was recorded from the three channel $C_3-A_1$, $C_4-A_2$ and $P_Z-A_1$. After averaging 16 times for each channel output, we extracted the features of specific mental tasks by modeling the output as 12th order AR coefficients. We used total 36th order coefficient as an input parameter of the neural network and measured the training data 50 times per each task. With data not used for training, the rate of task recognition is 34-92 percent on the two tasks, and 38-54 percent on the four tasks.

• Phonetics and Speech Sciences
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• v.13 no.2
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• pp.67-76
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• 2021

Nanta means "tapping" using percussion instruments such as drums, which is the rhythm of Samulnori, a tradtional Korean music. Nanta speech rhythm intervention program was developed and applied for the children with limited speech sound production and investigated its effect. Nanta program provided audible stimulation, various sound loudness and beats, and rhythms. Nanta program consists of three stages : Respiration, phonation and articulation with the rhythm. Six children with language development delay participated in this study. Children were encouraged to explore sounds and beats and freely express sounds and beats. Along with the rhythm, children also were encouraged to produce speech sounds by increasing the length of syllables in mimetic and imitating words. A total of 15 sessions were conducted twice a week for 40 minutes per session. For exploring the effectiveness, raw scores from preschool receptive-expressive scales (PRES) and receptive-expressive vocabulary test (REVT) were obtained and compared before and after therapy. The results demonstrated that significantly improved receptive (p=.027) and expressive language scores (p=.024) in PRES and receptive (p=.028) and expressive (p=.028) vocabulary scores following intervention using Wilcoxon signed-rank test.These findings suggest that the nanta rhythm program can be useful for improving language development and vocabulary in children with limited speech sound production.

• Korean Journal of Culture and Social Issue
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• v.11 no.2
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• pp.31-46
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• 2005

The purpose of the present study was to investigate the effects of in-vehicle noise types and levels of intensity on drivers' driving speed estimation. Noise generated from the vehicle engine and musical sound sampled from the Korean pop were employed as the types of in-vehicle noise and their levels of intensity were systematically manipulated. In experiment 1 where the effect of the engine noise levels on speed estimation was observed, drivers showed the tendencies of driving faster than the targets speeds under lower noise intensity condition whereas driving slower under higher noise intensity condition. In experiment 2 where both musical sample and the engine noise were provided, drivers' subjective speed estimation was affected by the engine noise as revealed experiment 1, but not by musical sample. When the data from the both experiments were combined and analyzed, an interacting effect of engine noise levels and music sample levels was found: if the intensity of music sample was enough to overwhelm the engine noise, the drivers drove faster than lower engine noise level condition in the experiment 1. This result indicates that although the music sample is not the direct auditory cue of speed estimation as observed in the experiment 2, intense level of music sample can affect drivers' speed estimation when it is coupled with the lower engine noise level.

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.265-270
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• 2006

최근의 휴대전화 단말기(Cellular Phone, CP)는 IT기술을 적극적으로 접목하여 다양한 기능을 부가하고 있으나, 단순한 IT기술의 접목만으로는 CP기술 발전의 한계를 드러내고 있다. 이러한 상황에서 휴대전화 단말기에 개인용 로봇(Personal Robot)을 결합하여 로봇의 개인 서비스 기능과 엔터테인먼트 기능을 갖춘 개인로봇형 휴대전화단말기인 RCP(Robotic Cellular Phone)의 개념을 도입한 연구가 진행되고 있다. 본 논문에서는 RCP세부기술 중 하나인 $RCP^{Interaction}$에 주목한 연구로, RCP의 촉각 및 청각자극환경에서 인간이 느끼는 감성을 생체신호를 활용하여 객관적으로 감성을 평가할 수 있는 시스템에 대한 연구를 수행 하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.661-662
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• 2017

가상현실(VR)은 현실 세계를 인공적인 기술을 활용하여 실제로 얻기 힘든 경험이나 환경 등을 제공해 인체의 오감(시각, 청각, 후각, 미각, 촉각)을 자극함으로써 실제와 같이 체험하게 하는 기술로써 게임, 영화, 스포츠, 테마파크와 같이 엔터테인먼트 목적으로 개발되는 경우가 많다. 본 논문에서는 Oculus Touch 및 Oculus Rift를 이용한 VR(Virtual Reality) 올림픽 종목의 스포츠를 설계하고 구현한 시스템을 제안한다. 올림픽 종목 중에 인기종목인 양궁, 사격, 테니스, 탁구 총 4가지 종목으로 구성되어 있으며, 특히 AI를 이용한 경쟁을 통해 종목별 스코어(점수)를 평가함으로서 경쟁구도를 형성한다. 또한, 시각적인 자극을 통해 흥미를 이끌어내고 현실적인 환경을 구현함으로써 유저가 실제 현장에 있는 것 같은 느낌을 제공하며, 세계적인 올림픽 스포츠를 유저들이 직접 즐기고 느낄 수 있다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.07a
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• pp.55-56
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• 2019

본 논문은 유아기 언어 발달 시기에 한글의 기초 단계를 학습하기 위해 기존의 교육 방식과는 달리 시각적, 청각적 효과로 몸의 감각을 통해 사물을 배우며 이러한 자극으로 정보를 기억하고 축적할 수 있는 에듀테인먼트 콘텐츠를 개발한다. 유아의 호기심을 자극할 뿐만 아니라 모바일 플랫폼과의 상호작용을 통해 재미와 즐거움을 키우며 나아가 지식을 얻을 수 있다.