• Korean Journal of Audiology
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• v.25 no.4
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• pp.235-240
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• 2021

Sudden sensorineural hearing loss (SSNHL) is a common disorder; however, sequential, bilateral presentation of the disease is rarer than unilateral presentation. Clinical otologists usually focus on treating the side with impaired hearing when patients first present with unilateral SSNHL, and therefore, may not warn patients of the possibility of subsequent hearing impairment in the contralateral ear. Furthermore, it is professionally discouraging when a patient presents with profound, sequential SSNHL after initial treatment. This may adversely impact the doctor-patient relationship, even if the patient is offered the best possible care from their first visit. Herein, we report the case of a patient with profound, idiopathic, bilateral SSNHL with a time interval of 37 days between involvement of both ears. Even though high-dose steroids were administered intraorally and intratympanically, the patient's hearing was not restored, and the patient eventually required bilateral cochlear implant surgery. Our report demonstrates that sequential, profound, bilateral SSNHL may manifest without any specific signs.

• Journal of Audiology & Otology
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• v.25 no.4
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• pp.235-240
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• 2021

Sudden sensorineural hearing loss (SSNHL) is a common disorder; however, sequential, bilateral presentation of the disease is rarer than unilateral presentation. Clinical otologists usually focus on treating the side with impaired hearing when patients first present with unilateral SSNHL, and therefore, may not warn patients of the possibility of subsequent hearing impairment in the contralateral ear. Furthermore, it is professionally discouraging when a patient presents with profound, sequential SSNHL after initial treatment. This may adversely impact the doctor-patient relationship, even if the patient is offered the best possible care from their first visit. Herein, we report the case of a patient with profound, idiopathic, bilateral SSNHL with a time interval of 37 days between involvement of both ears. Even though high-dose steroids were administered intraorally and intratympanically, the patient's hearing was not restored, and the patient eventually required bilateral cochlear implant surgery. Our report demonstrates that sequential, profound, bilateral SSNHL may manifest without any specific signs.

• Journal of the Optical Society of Korea
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• v.20 no.2
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• pp.269-275
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• 2016

This study has investigated the feasibility of 980-nm low-energy pulsed near-infrared laser stimulation to evoke auditory responses, as well as the effects of radiant exposure and pulse duration on auditory responses. In the experiments, a hole was drilled in the basal turn of the cochlea in guinea pigs. An optical fiber with a 980-nm pulsed infrared laser was inserted into the hole, orientating the spiral ganglion cells in the cochlea. To model deafness, the tympanic membrane was mechanically damaged. Acoustically evoked compound action potentials (ACAPs) were recorded before and after deafness, and optically evoked compound action potentials (OCAPs) were recorded after deafness. Similar spatial selectivity between optical and acoustical stimulation was found. In addition, OCAP amplitudes increased with radiant exposure, indicating a photothermal mechanism induced by optical stimulation. Furthermore, at a fixed radiant exposure, OCAP amplitudes decreased as pulse duration increased, suggesting that optical stimulation might be governed by the time duration over which the energy is delivered. Thus, the current experiments have demonstrated that a 980-nm pulsed near-infrared laser with low energy can evoke auditory neural responses similar to those evoked by acoustical stimulation. This approach could be used to develop optical cochlear implants.

• Phonetics and Speech Sciences
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• v.6 no.2
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• pp.55-64
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• 2014

This study measured formant bandwidths of profound hearing impaired children and examined the characteristics of their articulation. For this study, 10 cochlear implanted children(CI), 10 hearing aid children(HA) and 10 normal hearing children(NH) were asked to read 7 Korean vowels(/ɑ, ʌ, o, u, ɯ, i, ɛ/). The subjects' readings were recorded by NasalView and analyzed by Praat. The analysis of the formant bandwidths explains the degree of vocal fold opening and the characteristics of radiation. Through the analysis of formant bandwidth, we can see that the hearing-impaired maintain vocal fold tension when they speak high vowels and characteristics of radiation. Narrower B1 means better maintain vocal fold tension, wider B2 means more front and wider B3 means the rounder lips. CI's B1 was widest and NH's was narrowest. And females' B1 was wider than males'. Among vowels, B1 of /a/ was widest, and B1 of /i/ was narrowest. In the case of B2, HA and NH's B2 was wider than CI's. Females' B2 was wider than males'. And B2 of /i/ was widest, and B2 of /ʌ/ was narrowest. In the case of B3, NH's was widest, and CI's was narrowest. Males' was wider than females'. Among vowels, B3 of /o/ was widest, and B3 of /ɛ/ was narrowest. As a result, first, through the analysis of B1, we can find that NH and males could better maintain vocal fold tension than the hearing-impaired or females, and all children articulate /i/ with vocal fold tension than other vowels. Second, through the analysis of B2, NH and HA articulate vowels with the weaker rounded than CI does. And females articulate vowels with the weaker rounded than males do. Third, through the analysis of B3, NH articulate vowels with the rounder than HA or CI do, and males articulate vowels with the rounder than females do. Through the results, we can expect that the analysis of formant bandwidth will be applied to the therapy of articulation for the hearing-impaired with hearing aids or cochlear implant.

• Speech Sciences
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• v.9 no.2
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• pp.193-202
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• 2002

The purpose of this study is to examine the phonological awareness of hearing impaired children. A number of researches indicate that hearing impaired children have articulation disorders due to their impaired auditory feedback. However, in children who have the ability to distinguish certain phonemes, they sometimes show misarticulation of the phonemes. Phonological awareness refers to recognizing the speech-sound units and their forms in spoken language (Hong, 2001). The subjects who participated in the experiment are composed of four hearing impaired children (3 cochlear implanted children and 1 hearing aided child). Phonological Awareness was evaluated by the test battery developed by Paik et al. (2001). The subtests consisted of rhyme matching, onset matching I II, word initial segmentation and matching I II. If the children asked for retelling, it was retold to a maximum of 4 times. Each item score was 1 point. The results were compared to those of Paik et al. (2001). The results of study were that subject 1 showed superior rhyme matching ability, subjects 2 and 3 fair ability, and subject 4 inferior ability. In onset matching I, all subjects showed inferior ability except for subject 3. Interestingly, subjects 1 showed the lowest onset matching I score. In word initial segmentation and matching I, subjects 1 and 4 showed inferior ability and subjects 2 and 3 showed fair ability. In onset matching II, subject 2 showed the perfect score 10 even though she showed very low score. In word initial segmentation and matching II, only subjects 2 and 3 showed appropriate levels of the skill. The results show that the phonological awareness of hearing impaired children is different from that of normal children.

• The Journal of the Acoustical Society of Korea
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• v.24 no.7
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• pp.379-386
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• 2005

Among various kinds of hearing aids which have been developed so far. the conventional air conduction hearing aids have some problems such as the acoustic distortion, an howling effect due to acoustic feedback. Another type of hearing aid. the cochlear implant system can be applied to the profound imparied person. However. it shows the disadvantage that there is no possibility of recovery of the acoustic organ such as ossicle. On the other hand. the implantable middle ear heaving device directly vibratos the ossicular chain and has better sound qualify. good cosmetics for appearance. and wide frequency responses so that it can overcome the defects or the conventional hearing aids. In this paper, a mathematical modeling and a momentum equation derivation of the DET has been performed. For the optimization of the structure dimension generating maximal vibrating force of the DET. the computer simulation using a finite element analysis (FEA) software has been performed. Also. the vibrating transducer has been designed to make the frequency characteristics or the transducer be similar to those of the normal middle ear. Through the experimental results, the measured vibration characteristics of the DET has been evaluated to verify the performance for the application to implantable middle ear hearing devices.

• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.375-385
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• 2016

Recently, several implantable hearing aids such as cochlear implant, middle ear implant, etc., which have a module receiving power and signal from outside the body, are frequently used to treat the hearing impaired patients. Most of implantable hearing aids are adopted permanent magnet pairs to couple between internal and external devices for the enhancement of power transmission. Generally, the internal device which containing the magnet in the center of receiving coil is implanted under the skin of human temporal bone. In case of MRI scanning of a patient with the implantable hearing aid, however, homogeneous magnetic fields of the MRI might be interfered by the implanted magnet. For the above reasons, the MR image is degraded by large area of artifact, so that diagnostics are almost impossible in deteriorated region. In this paper, we proposed an external coil system that can reduce the artifact of MR image due to the internal coupling magnet. By finite element analysis estimating area of MR artifact according to varying current and shape of the external coil, optimal coil parameters were extracted. Finally, the effectiveness of the proposed external coil system was verified by confirming the artifact at real MRI scan.

• Journal of Sensor Science and Technology
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• v.23 no.3
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• pp.178-184
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• 2014

Key components of implantable hearing aids are consist of an acoustic sensor that collect external sound by suppressing the body noise, a signal processor module for compensation algorithm of hearing loss, and a output transducer which has tiny size but have high efficiency, respectively. In the partial implantable hearing aids, technologies of transducer and signal processor are so matured that can be applied not too much difficulty. However, due to the difficulties in implantable acoustic sensor technology, such as minimization of masticatory sound and damage of sensor's membrane from external impact, practical use of fully implantable hearing aids have not successful so far. In this paper, we have proposed a novel implantable acoustic sensor which has trans-tympanic structure, and is verified that the proposed method can be very useful for fully implantable hearing aids by cadaveric experiments.

• Korean Journal of Digital Imaging in Medicine
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• v.17 no.1
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• pp.49-56
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• 2015

Temporal bone CT scan side skull fracture. In addition to the confirmation of the ossicles, such as fractures and dislocations, temporomandibular facial fractures, deformities surgery helps to establish a science plan. Cochlear implant surgery has been performed in the state before and after identifying purposes. Test methods are being implemented by the Conventional direct axial and Direct coronal scan, the basic method of Temporal bone CT. Helical scan is a fast Volumetric data obtained compared with the Conventional scan, the patient reduced the dose, and there are some advantages, such as reduced Beam hardening streak artifacts caused by dental fillings. This study is a comparative analysis by dose reduction for patients with a dose according to the conventional scan method and then effective from 2015 by helical scan method performed in 2014 through the retrospective survey, which was then optimized for the purpose of inspection.

• Phonetics and Speech Sciences
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• v.7 no.2
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• pp.9-17
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• 2015

In the present study, we investigated ability of recognition of auditory perception with regards to the quality of voice in postlingual CI adults and proposed a training program to improve within subject reliability. A prospective case-control study was conducted in adults with 7 postlingual deaf who received a CI surgery and 10 normal hearing controls. The pre and post test and training program included parameters of consensus auditory-perceptual evaluation of voice(CAPE-V) with pathological voice sample by using Alvin. In results of pre-post test for monitoring improvements of internal reliability for listeners via the training program, there was statistically significant difference in both test and group. There was statistically significant difference in internal reliability between pre-post test in the normal hearing group, the result was no significant in the CI group. The present study found that CI adults showed less ability in awareness of voice quality compared to normal hearing group. Also the training program improved pitch and loudness in CI adults.