• Proceedings of the KOR-BRONCHOESO Conference
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• 1978.06a
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• pp.9.1-10
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• 1978

Recently the authors have observed various wave-forms by insertion of induction coil into the scala tympani as well as attached outer device in the outside of the body in damaged hair cells of the cats. In the cochlear nerve. action potential indicated different polarities induced by examination of the bundle of the cochlear nerve fibers. Impulse wave-form as a result of excitation of cohlear nerve fibers showed bipolar wave-form such as negative 1 and positive 1. Therefore action potential showed also bipolar wave-form as above mentioned. We can obtained suitable response with above mentioned outer and inner device as an exact oscillogram.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.249-255
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• 2012

A cochlear implant system uses charge-balanced biphasic pulses that are known to reduce tissue damage than monophasic pulses. In this study, we investigated effect of pulse pattern on neural responses using a computer model, based on the Hodgkin-Huxley equation. Electric pulse phase, pulse duration, and phase gap have been systematically varied to characterize auditory nerve responses. The results show that neural responses, dynamic range and threshold are represented as a function of stimulus patterns and duration. The results could greatly extend to develop more efficient cochlear implant stimulation.

• Proceedings of the KSPS conference
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• 2007.05a
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• pp.302-304
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• 2007

The purpose of this study was to evaluate speech production ability of congenitally deaf children with cochlear implant. Forty children were participated in the study. The results are following: (1) mean of speech intelligibility score was 3.05 in 5 point scale, (2) mean of percent of correct vowels was 86.19%, and mean of percent of correct consonants was 74.89%, and (3) voice profiles showed their voice were high pitched, hypernasal, and breathy. But 12.5% of the children were evaluated as having normal voice quality. Overall speech production abilities of children with cochlear implant were superior than the deaf children's result reported in literatures. Meanwhile their abilities were not same as children with normal hearing.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.163-164
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• 1998

In this paper the digital speech processing part of cochlear implant for sensorineural disorderly patients is implemented and simulated. We implement the speech processing part by dividing into three small parts - Filterbank, Pitch Detect, and Bandmapping parts. With the result, we conclude digital speech processing algorithm is implemented in FPGA perfectly. This means that cochlear implant can be made very small size.

• Journal of radiological science and technology
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• v.22 no.2
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• pp.27-32
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• 1999

Cochlear implant poses a contraindication to the magnetic resonance imaging(MRI) process, because MRI generates artifacts, inducing an electrical current and causing device magnetization. CT is relatively expensive and the metal electrodes scatter the image. Post-implantation radiological studies using anterior-posterior transorbital, submental-vertex and lateral views, the intracochlear electrodes are not well displayed. Therefore, the authors developed a special view, which we call the cochlear view. The patient is sitting in front of a vertical device. Then the midsagittal plane is adjusted to form an angle of $15^{\circ},\;30^{\circ}$, and $45^{\circ}$ with the film. The flexion of the neck is adjusted to make the infraorbitomeatal line(IOML) is parallel with the transverse axis of the film. The central ray is directed to exit from the skull at point which is 3.0 cm anterior and 2.0 cm superior to the EAM(external auditory meatus). Results have shown that single radiography of the cochlear view provides sufficient information to demonstrate the position of the electrodes array and the depth of insertion in cochlear. Radiography of the cochlear view in angle of $45^{\circ}$ is an excellent image. The cochlear view gives the greatest amount of medical information with the least radiation and lowest medical cost. It can be widely used in all cochlear implant clinics.

• Journal of Preventive Medicine and Public Health
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• v.37 no.4
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• pp.353-358
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• 2004

Objective : To determine the quality of life and cost consequences for deaf adults who received a cochlear implant. Methods : The data from 11 patients, post-lingual deaf adults who received cochlear implants from 1990 to 2002, underwent cost-utility analysis. The average age of the participants was 49.6 years. The main outcomes were direct cost per quality-adjusted life-year (QALY) using the visual analog scale (VAS), health utility index (HUI), EuroQol (EQ-5D), and quality well-being (QWB), with costs and utilities being discounted 3% annually. Results : Recipients had an average of 5.6 years of implant use. Mean VAS scores increased by 0.33, from 0.27 before implantation to 0.60 at survey. HUI scores increased by 0.36, from 0.29 to 0.65, EQ-5D scores increased by 0.26, from 0.52 to 0.78, and QWB scores increased by 0.16, from 0.45 to 0.61. Discounted direct costs were $22,320, yielding $19,223/QALY using VAS, $17,387/QALY using HUI, $24,604/QALY using EQ-5D, and $40,474/QALY using QWB. Cost-utility ratios using VAS, HUI, and EQ-5D were all below $25,000 per QALY, except using QWB. Conclusion : Cochlear implants in post-lingual deaf adult have a positive effect on quality of life at reasonable direct costs and appear to produce a net saving to society.

• Speech Sciences
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• v.9 no.1
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• pp.27-38
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• 2002

The purpose of the study is to examine intonation patterns of cochlear implanted children compared with those of normal hearing children. The data tokens of three normal and five cochlear implanted children were collected and investigated. Their intonation patterns were analyzed using the speech analysis tool, Praat. The characteristics of the two utterance types, interrogative and declarative, were investigated. No significant difference in intonation patterns between the two subject groups was found. However, the general pitch of cochlear implanted children was higher than that of normal hearing children. In addition, cochlear implanted children showed frequent pitch breaks.

• Journal of Audiology & Otology
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• v.23 no.3
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• pp.135-139
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• 2019

Background and Objectives: This study was undertaken to investigate the educational status in bilateral prelingual deaf children with a cochlear implant (CI), also known as early cochlear implantees (CIs). Type of schooling and enrollment rate of tertiary education were analyzed as primary results. Subjects and Methods: Participants in this study comprised a highly homogeneous group of deaf patients who underwent cochlear implantation at a similar age. Sixty-four Korean patients were enrolled. Statistical data for disabled populations and the general population were obtained from the National Statistics Korea. Results: Among 64 patients, 46, 8, and 10 attended mainstream, integrated, and special schools, respectively. Notably, there was a significant difference in the type of school between hearing-impaired and CI groups (p=0.007). Ten of 13 patients enrolled in tertiary education. Conclusions: CI users were more likely than hearing impaired students to attend mainstream school. The enrollment rate of CI users in tertiary education was the same as that of the general population.

• Korean Journal of Audiology
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• v.23 no.3
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• pp.135-139
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• 2019

Background and Objectives: This study was undertaken to investigate the educational status in bilateral prelingual deaf children with a cochlear implant (CI), also known as early cochlear implantees (CIs). Type of schooling and enrollment rate of tertiary education were analyzed as primary results. Subjects and Methods: Participants in this study comprised a highly homogeneous group of deaf patients who underwent cochlear implantation at a similar age. Sixty-four Korean patients were enrolled. Statistical data for disabled populations and the general population were obtained from the National Statistics Korea. Results: Among 64 patients, 46, 8, and 10 attended mainstream, integrated, and special schools, respectively. Notably, there was a significant difference in the type of school between hearing-impaired and CI groups (p=0.007). Ten of 13 patients enrolled in tertiary education. Conclusions: CI users were more likely than hearing impaired students to attend mainstream school. The enrollment rate of CI users in tertiary education was the same as that of the general population.

• The Journal of the Acoustical Society of Korea
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• v.41 no.1
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• pp.45-51
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• 2022

Sound quality evaluation is one of the psychoacoustic methods to measure subjective judgements for sound color. The purpose of this study is to investigate sound quality benefits of bimodal users by comparing sound quality scores between bimodal hearing condition and unilateral cochlear implant(CI) condition as a preliminary study. Thirteen bimodal users and seven unilateral CI users were participated in this study. Audiologists performed pure tone and speech audiometry and measured functional gain and real-ear insertion gain. Subjective assessment of sound quality was followed with four sounds including violin sound, male and female voices, and refrigerator noise. Participants judged the sound quality with six sound quality index. Bimodal users showed mean 0.8 points more sound quality improvements in bimodal condition than unilateral CI condition. Group comparison between bimodal and unilateral CI users showed no differences. A follow-up study of sound quality tools and methods should be considered to evaluate subjective bimodal benefits of cochlear implant users.