• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.284-286
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• 1993

Software and hardware for cochlear implant system have been developed to create a speech signal processing system which, in real-time, extracts model parameter including formants, pitch, amplitude information. The system is based on the Texas Instruments TMS320 family. In hardware, computer interface has been desisted and implemented that allows presentation of biphasic pulse stimuli to patients with the hearing handicapped. The host computer sends a stream of bytes to the parallel port. Upon receipt of the data the interface generates the appropriate burst sequence that is delivered to the patient's external transmitter coil. The coded information is interpreted by the Nucleus-22 internal receiver that delivers the pulse to the specified electrodes at the specified amplitude and pulse width.

• Korean Journal of Audiology
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• v.25 no.1
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• pp.1-7
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• 2021

The scope of teleaudiology has been noted with telehealth due to Coronavirus disease (COVID-19) recently. As the notion has been around us for more than 20 years ever since 1999, it is necessary to perceive the knowledge accurately and prepare for the successful implementation of it. Therefore, the literature review including screening and diagnostic audiometry, cochlear implants and hearing aids, and aural rehabilitation, telecommunications technology regarding several fields of teleaudiology, and considerations for practicing were identified. Although overall internet-based audiological services showed benefits in terms of outcome and accessibility, uncertainties of cost-effectiveness, the optimal level of support, and a need for further studies of many aspects for teleaudiology has arisen. In the view of technology, the store-and-forward (asynchronous/hybrid) and a real-time (synchronous) methods were introduced with one applied and nine registered patents recorded from 2004 to 2020 for the invention of teleaudiology in the United States. Also, 10 checklists were suggested for planning teleaudiology practice from prior experience in hosting the teleaudiology program. Conclusively, it is hoped that this review sheds light on recognizing and improving the existing teleaudiology services and helps overcome the challenges faced in the era of pandemic and untact world to come.

• Journal of Audiology & Otology
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• v.25 no.1
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• pp.1-7
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• 2021

The scope of teleaudiology has been noted with telehealth due to Coronavirus disease (COVID-19) recently. As the notion has been around us for more than 20 years ever since 1999, it is necessary to perceive the knowledge accurately and prepare for the successful implementation of it. Therefore, the literature review including screening and diagnostic audiometry, cochlear implants and hearing aids, and aural rehabilitation, telecommunications technology regarding several fields of teleaudiology, and considerations for practicing were identified. Although overall internet-based audiological services showed benefits in terms of outcome and accessibility, uncertainties of cost-effectiveness, the optimal level of support, and a need for further studies of many aspects for teleaudiology has arisen. In the view of technology, the store-and-forward (asynchronous/hybrid) and a real-time (synchronous) methods were introduced with one applied and nine registered patents recorded from 2004 to 2020 for the invention of teleaudiology in the United States. Also, 10 checklists were suggested for planning teleaudiology practice from prior experience in hosting the teleaudiology program. Conclusively, it is hoped that this review sheds light on recognizing and improving the existing teleaudiology services and helps overcome the challenges faced in the era of pandemic and untact world to come.

• Molecules and Cells
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• v.38 no.9
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• pp.781-788
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• 2015

Mutations of MYO15A are generally known to cause severe to profound hearing loss throughout all frequencies. Here, we found two novel MYO15A mutations, c.3871C>T (p.L1291F) and c.5835T>G (p.Y1945X) in an affected individual carrying congenital profound sensorineural hearing loss (SNHL) through targeted resequencing of 134 known deafness genes. The variant, p.L1291F and p.Y1945X, resided in the myosin motor and IQ2 domains, respectively. The p.L1291F variant was predicted to affect the structure of the actin-binding site from three-dimensional protein modeling, thereby interfering with the correct interaction between actin and myosin. From the literature analysis, mutations in the N-terminal domain were more frequently associated with residual hearing at low frequencies than mutations in the other regions of this gene. Therefore we suggest a hypothetical genotype-phenotype correlation whereby MYO15A mutations that affect domains other than the N-terminal domain, lead to profound SNHL throughout all frequencies and mutations that affect the N-terminal domain, result in residual hearing at low frequencies. This genotype-phenotype correlation suggests that preservation of residual hearing during auditory rehabilitation like cochlear implantation should be intended for those who carry mutations in the N-terminal domain and that individuals with mutations elsewhere in MYO15A require early cochlear implantation to timely initiate speech development.

• Journal of Music and Human Behavior
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• v.14 no.1
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• pp.1-16
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• 2017

The purpose of this study was to examine changes in the accuracy and range of produced pitch in children with cochlear implants (CI) after an interval-based singing program. A total of three children with CIs aged 5 received twelve 35-minute individual sessions two to three times per week. The interval-based singing program was composed with third, fifth, and eighth intervals and implemented pitch discrimination, pitch imitation, and singing songs with target intervals in a sequence. At pretest and posttest, the changes in accuracy of pitch production during pitch imitation and singing were measured. The results demonstrated that all participants showed improvement in pitch accuracy and produced the target notes with great similarity to the expected pitches in the original song. The range of produced pitch also increased after the program. The results indicate that sequential trials to imitate pitches in a multisensory environment to facilitate the processing of pitch information may reflect how this population perceives pitch information and assist children with CIs to improve their pitch accuracy.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.5 s.311
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• pp.79-87
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• 2006

In this study, we evaluated the performance of a companding strategy as a preprocessing for speech enhancement and noise reduction. The proposed algorithm is based on two tone suppression that is human's hearing characteristics. This algorithm enhances spectral peak of speech signal and reduces background noise, however it has tradeoff characteristics between speech distortion and noise reduction due to limited channel number and nonlinear block. Therefore, we designed two different companding structures that have relative characteristics of noise reduction and speech distortion and found suitable companding structures by difference of individual speech perception ability in noise environment. Thus we proposed speech perception enhancement of cochlear implant user in noise environment with low SNR. The performance of the proposed algorithm was evaluated through 5 normal hearing listeners using noise band simulation. Improvement of speech perception was observed for all subjects and each subject preferred the different type of companding structure.

• Journal of Life Science
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• v.18 no.4
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• pp.542-549
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• 2008

Cisplatin (cis-diamminedichloroplatinum II : CDDP) is the most widely used anticancer drug against a variety of human neoplasms. However, its clinical use is limited by the onset of severe side effects, including ototoxicity and nephrotoxicity. Even though a number of evidences in cytotoxic mechanism of cisplatin have been suggested, the role of pro-inflammatory cytokines in cisplatin cytotoxicity of auditory cells has not yet been demonstrated. Herein our data clearly demonstrated that cisplatin decreased the viability of HEI-OC1 auditory cells, which was inhibited by the addition of neutralizing $anti-TNF-{\alpha}$, $anti-IL-1{\beta}$ and anti-IL-6 antibodies. Consistently, Neutralization with antibodies against pro-inflammatory cytokines ameliorated the cell death and disarrangement of cochlea hair cell layers in the rat primary cochlear explants which were treated with cisplatin. Furthermore, exogeneous supplementation with free radical scavengers, including GSH and NAC, significantly prevented the cytotoxicity of cisplatin in the rat primary cochlea explants. We also observed that $TNF-{\alpha}$ was predominantly expressed in Deiters and Hensen's cells located in hair cell zone of cisplatin-treated cochlear explants. These findings suggest that pro-inflammatory cytokines, including $TNF-{\alpha}$, $IL-1{\beta}$ and IL-6, may play a pivotal role in the pathophysiology of hair cell damages caused by ototoxic drug cisplatin.

• Journal of Music and Human Behavior
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• v.15 no.2
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• pp.69-92
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• 2018

The purpose of this study was to investigate whether a songwriting intervention would improve self-expression of adolescents with cochlear implants (CI). In this study, the songwriting intervention was designed to incorporate previous research findings on music perception of individuals with CIs and to provide musical experiences in which adolescents with CIs could be successful in using music resources for their self-expression. Accordingly, stepwise songwriting procedures were constructed and music technology (i.e., GarageBand as an iPad application) was used. Two adolescents with CIs participated in the intervention once a week for 8 weeks. Changes in level of participation in songwriting tasks, verbal expression, self-reports about the songwriting process were examined. The results demonstrated that the participants showed increased attempts to express themselves via music making. It was also shown that their negative perception of their ability to verbally express themselves decreased. They were observed as becoming more competent in creating music by deciding how various musical elements should be played and making rhythm or melodic patterns by themselves. These results indicate that the songwriting intervention can facilitate self-expression of adolescents with CIs. Further implications in terms of the psychosocial needs of individuals with CIs are presented.

• Phonetics and Speech Sciences
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• v.14 no.2
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• pp.77-86
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• 2022

This study aimed to investigate the voice onset time (VOT) of plosives in the VCV syllables by the place of articulation and phonation type spoken by children with bilateral cochlear implants (CIs) in comparison with children with typical hearing (TH). In all, 15 children with bilateral CIs and 15 children with TH participated in this study, aged between 5 to 10 years. All children produced 9 VCV syllables and their VOT were analyzed by the Praat software. There was no significant difference in mean VOT between children with bilateral CIs and children with TH. However, there was a significant difference in mean VOT by the place of articulation, such that the VOT for velars were longer than those for bilabials and alveolars. Additionally, there was a significant difference in mean VOT by the phonation type, such that the VOT of aspirated consonants were longer than those of lenis and fortis consonants. The results of this study suggest that children with bilateral CIs can distinguish the acoustic properties of plosive consonants and control the speech timing between the structures of the larynx and the oral cavity at a similar level as children with TH.

• Journal of Audiology & Otology
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• v.23 no.3
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• pp.153-159
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• 2019

Background and Objectives: We aim to explore the effects of residual auditory steady state response (ASSR) on cochlear implantation (CI) outcomes in children lacking auditory brainstem responses (ABRs). Subjects and Methods: We retrospectively reviewed the data of child CI recipients lacking ABRs. All ears were divided into two groups: with residual ASSR and without ASSR. For each frequency, the T- and C-levels and the electrical dynamic ranges of postoperative 3-month and 1-year mappings were compared between the groups. To evaluate speech perception, patients who received simultaneous bilateral CIs were divided into two groups: group 1 exhibited responses at all frequencies in both ears; in group 2, at least one ear evidenced no response. The Categories of Auditory Perception (CAP) and Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) scores were compared between the groups. Results: We enrolled 16 patients. At 2 kHz, the postoperative 3-month and 1-year T-levels of patients with residual hearing were lower than those of hearing loss group (p=0.001, p=0.035). In residual hearing group, the ASSR threshold correlated positively with the postoperative 1-year T-level (p=0.012, R²=0.276) and C-level (p=0.002, R²=0.374). Of 10 simultaneous bilateral CI recipients, 5 exhibited ASSRs at all frequencies and the other 5 showed no response at ≥1 frequency. The latter had higher CAP scores at the postoperative 1-year (p=0.018). Conclusions: In children exhibiting hearing loss in ABR testing, residual hearing at 2 kHz ASSR correlated positively with the post-CI T-level. Those with ASSRs at all frequencies had significantly lower CAP scores at the postoperative 1year. CI should not be delayed when marginal residual hearing is evident in ASSR.