이명이 없는 정상인의 이명 설문 결과

허승덕,문윤국,이강현 한국언어치료학회 2015 한국언어치료학회 학술발표대회 논문집 Vol.2015 No.12

음장과 외이도 내부에서의 음성 비교

허승덕,김리석,고도흥,이정학 한국음성과학회 2000 음성과학 Vol.7 No.4

외이도 내부의 음성은 음원에서부터 매질인 음장 그리고 청각 기관의 말단인 외이도까지 다양한 조건에 의해 변화하였는데, 발성기관과 음장의 상호 작용에 의해 모든 대상 모음의 F_1, F_2와 조음위치가 높은 모음의 F_3, F_4, F_5가 음장의 감쇄에 의해서는 /a/의 F_4, F_5와 /i/와 /u/의 F_3, F_4, F_5가 머리와 이개의 간섭의 의해 /a/의 F_1, F_2, /i/의 F_2가 그리고 외이도의 구조 및 공명에 의해 /a/의 F_1, F_3와 /i/의 F_3, F_5가 각각 낮아지거나 높아졌으며, 조음 위치가 높은 모음에서는 전설보다 후설모음에서 그리고 조음위치가 높은 모음보다 낮은 모음에서 더 큰 변화를 보였다. 외이도 내부에서의 음성은 음장을 지나 온 음원에 대한 외이도의 좁아진 공간뿐만 아니라 구강 공간의 크기, 구강 전반부 및 인가의좁힘 등의 발화 요인과 음장 조건 등에 의해서도 영향을 받고 있었으며, 외이도 공명 주파수를 중심으로 각각의 모음 앞쪽과 뒤쪽 포먼트 주파수 및 강도 변화 양상으로 보아 음성의 인지보다는 음성의 식별과 관련된 것으로 추정된다. 더욱이 본 연구결과의 활용을 위해 보다 많은 실험 단어와 음성 분석 지료를 사용한 연구가 필요하겠다. The purpose of this study was to examine some acoustic chracteristics in the ear canal. It was assumed that a sound outside the external auditory canal could be different from the sound inside the external auditory canal. The acoustic signals were captured by a probe microphone placed at a distance within 1 cm from the tympanic membrane, and a reference microphone was placed over the upper pinna. Three vowels /a/, /i/, /u/ were recorded from a normal adult male speaker. The parameters such as the formant frequency (F1~F5) and the peak intensity were measured using a speech analyser, PCquirer. It was found that the entering part of the external auditory canal functions as a narrowing point as to the speech that passes through the free field. Results show that acoustic characteristics were chaned for speech discrimination rather than speech perception. Keywords : free field, external auditory canal, speech discrimination

전기 자극 청신경 복합활동전위: 변인 영향

허승덕 한국재활복지공학회 2014 재활복지공학회논문지 Vol.8 No.1

Electrical compound action potential (ECAP) can be recorded on cochlear implant. This study will investigate stimulation and recording to enhance the efficacy of ECAP. 34 articles was used. We analyzed pulse and stimulating condition, artifact suppression, recording condition. The cathod-leading biphasic pulse was used with as short as possible pulse width and inter phase gap for the efficacy of neural firing, stable threshold and preventing neural degeneration. Around C-level was stimulated to apical, middle and basal turn of cochlea. Artifact was eliminated by forward-masking, template-subtraction technique. For clearer waveform, we need to change distance between stimulating and recording electrode, the gain of amplification, number of average. 전기 자극 청신경 복합활동전위(electrical compound action potential; ECAP)는 인공와우로 청신경을 자극하고 동시에 반응을 기록한다. 이 연구는 인공와우에서 ECAP의 효용성을 높이기 위하여 자극과 기록에 대하여 연구하고자 한다. 대상은 문헌 또는 사례 연구를 제외한 연구 논문 34 편으로 하였다. 연구는 펄스 및 자극 조건, 잡파 억제 및 기록 조건 등을 분석하였다. 효과적인 신경 발화, 안정적인 역치 확인, 신경 퇴행 방지 등을 위해서는 펄스폭과 위상 간격이 가급적 짧고, (-)위상이 앞선 양위상 펄스를 사용하였다. 자극은 펄스 간격, 자극비율, 자극 방식 등을 정하여 와우의 첨부, 중간, 기저회전으로 C-level 정도로 하였다. 잡파는 전방차폐법, 거푸집소거법으로 제거하였고, 분명한 파형을 획득하기 위해서는 전극 간격, 증폭 정도, 평균 가산 회수 등의 추가 조절이 필요하다.

이명 평가 App 개발

허승덕,이지은,이상흔 한국언어치료학회 2015 한국언어치료학회 학술발표대회 논문집 Vol.2015 No.12

순음청각선별 App 효용성 평가

허승덕,이민영,정다영,방채령,김준환 한국언어치료학회 2015 한국언어치료학회 학술발표대회 논문집 Vol.2015 No.12

정상 성인에서 청성유발 피부전위

허승덕,정동근,서덕준,김광년,김기련,강명구,김리석,Heo, Seung-Deok,Jung, Dong-Keun,Suh, Duk-Joon,Kim, Gwang-Nyeon,Kim, Gi-Ryon,Kang, Myung-Koo,Kim, Lee-Suk 한국음성학회 2005 음성과학 Vol.12 No.2

Electrodermal activity(EDA) is a bio-electric signal which occurs at the skin surface during the sweating. EDA reflects the activity of the sympathetic axis of the autonomic nervous system. EDA is associated with the eccrine sweat gland at the palmar and plamar surface. This study was aimed to characterize the relationship between EDA and auditory stimulus intensities. Acoustic stimulus used in this study were 500 Hz, 1 kHz, 2 kHz of narrow band noise, which were representative of speech frequencies in audible range. Stimulus intensity between 90 and 30 dB in 10 dB within dynamic range. After deriving the minimum stimulus intensity(threshold of skin potential) which elicited skin potential, and then the latency and amplitude were derived from waveform of skin potential, each latency and amplitude were compared to stimulus intensity. The waveform of skin potential were recorded stably, and the threshold of skin potential appeared nearly the hearing threshold level of the participant. The latency was decreased and the amplitude was increased according to the increase of the stimulus intensity. These results suggest that auditory evoked skin potential can be applicable to auditory assessment and audiological diagnosis tool.

편측 인공와우 이식자의 보청기 사용

허승덕,김리석,정동근,최아현,고도홍,김현기,Heo, Seung-Deok,Kim, Lee-Suk,Jung, Dong-Keun,Choi, Ah-Hyun,Ko, Do-Heung,Kim, Hyun-Gi 한국음성학회 2005 음성과학 Vol.12 No.4

The cochlear implantation(CI) as an useful tool for aural rehabilitation in bilateral severe to profound hearing impairment. However, CI prefer to usually one ear in spite of bilateral hearing impaired. because of the various characteristics of hearing loss, the hearing conservation for the future possibility, and socioeconomic condition of hearing impaired person and their families. The unilateral CI has limitations such as a directional loss, a difficult speech understanding in noise and a neural plasticity. These limitations will be overcome by hearing aid(HA) which is familiar with hearing impairer. but HA fitting for bimodal-binaural hearing are difficult because the difference output characteristic of HA and CI. This study will be confirm realities of use of HA in unilateral cochlear implantee. For this goal, 25(m:f=10:15) child participated who are used to HA for 1 to 17 months. We had telephone interviews with their mother about use of HA, change of auditory performance and own voice. As the results, hearing threshold levels of unimplanted ear, the use of a appropriate HA, implanted and aided hearing threshold level(HTL) are must be considered for successful biomodal-binaural hearing. Especially, implanted and aided HTL should be very useful parameter for a prediction of HA effect and a criterion of selection for bilateral cochlear implantation.

와우 전음성 난청

허승덕,소원섭 한국언어치료학회 2012 한국언어치료학회 학술발표대회 논문집 Vol.2012 No.12

와우 갑각 전기자극 뇌간유발반응용 원추형 전극의 개발

허승덕,정동근,강명구,김리석,고도흥 한국음성과학회 2003 음성과학 Vol.10 No.4

This paper introduces a new zinc coated copper wire electrode with coiled cone shape which has low surface resistance and tolerance to the motion artifact for promontory stimulation electrically auditory brainstem responses (PSEABR). Auditory brainstem responses (ABR) can be used to predict hearing threshold level with a great deal of accuracy particularly for a young child who cannot cooperate mechanically and some hearing impaired who are exaggerating a hearing loss for economic compensation. While severe profound sensorineural hearing losses may not be implemented by auditory potentials, PSEABR is proven as a useful tool even for some sensorineural related hearing impaired. It was shown that PSEABR gives the electrical stimuli to promontory of the cochlear instead of giving acoustic stimuli. For this reason, PSEABR can be used as an alternative for cochlear implantation, and can also be used as an optimal device selection and neural information for MAP. It was found that the role of electrode is very important in PSEABR. Even though this cone-shaped electrode was applied in animal experiments, waveforms are well produced by PSEABR. Thus, it was concluded that cone-shaped electrode turned out to be a useful preoperative audiological evaluation tool in deciding time for cochlear implantation surgery.

인공와우 이식자에서 자극 잡파를 이용한 고장 평가

허승덕,김상렬,안중기,정동근,강명구,Heo, Seung-Deok,Kim, Sang-Ryeol,Ahn, Joong-Ki,Jung, Dong-Keun,Kang, Myung-Koo 한국음성학회 2007 음성과학 Vol.14 No.2

The aim of this study is to analyze the correlation between current intensity and amplitude of stimulus artifact on the cochlear implantee, and to find out basic information to check the device failure. Subjects were a prelingual child and 3 postlingual adults with more than severe hearing losses. The charge-balanced biphasic pulses were presented at stimulus rates of 11 pulses per second, each pulse width of $25{\mu}s$ with monopolar mode(MP1+2). Current intensities were delivered at 27.5, 33.7, 41.3, 50.5, 61.9, $75.8{\mu}A$. Stimulus artifacts were recorded by evoked potential system. This procedure was performed just before the initial stimulation, and then, the amplitude of stimulus artifacts were compared with each current intensity. The amplitude of stimulus artifacts was increased significantly according to the current intensity (p<0.01). The results suggest that the change of the amplitude of stimulus artifact can be used as a good cue to check the device failure in the cochlear implantee.