• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.2
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• pp.186-192
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• 2012

Noise is a major cause of hearing loss in the air base. There are lots of risk factors of hearing loss including noise, and hearing loss can be accelerated by combined effects of these risk factors. Here in, we reviewed risk factors of hearing loss, and analysed key risk factors inducing hearing loss in the air base. Risk factors exacerbating hearing loss with noise were mainly investigated in this research because noise could not be an avoidable risk factor in the air base. Analysed data will contribute to make green environment minimizing hearing loss of pilots and supporting personnels in the air base.

• Journal of the Korean Society of Safety
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• v.28 no.4
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• pp.103-106
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• 2013

During a military service, noise has unusual characteristics, and constitutes a serious hazard to hearing of military servicemen. The purpose of this study is to understand the use of hearing protection and to assess the safety effects of hearing protection by using a ear plug in military. A total of 208(the army : 101, an air force : 107) serviceman were studied utilizing a questionnaire to know how many serviceman use the hearing protection and a total of 202(the army : 110, an air force : 92) serviceman were also studied using a ear fit validation device to assess the safety effects of hearing protection by using a ear plug. The results showed that the army have low used of hearing protection than an air force because of the low frequency of the noise exposure in the army. Personal attenuation rate was increased with 8 dB after fitting education. Therefore, it is recommended that use of proper hearing protection and fitting education was more suitable for military servicemen who were being exposed of the noise in domestic military.

• Phonetics and Speech Sciences
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• v.4 no.3
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• pp.179-186
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• 2012

The aims of this study are to consider auditory physiological characteristics and to confirm audiological evaluation and interpretation in regards to cases of sensorineural hearing loss that observe an abnormal AB gap. Vestibulosaccular hearing occurs when there is an abnormally large air-bone gap (AB gap) in sensorineural hearing loss, also known as pure cochlear conductive hearing loss. Generally, an AB gap is caused by damage to the external and/or middle ear. In conductive hearing loss, loss of air condition hearing occurs due to a loss of resonance in the outer ear and/or impedance mismatching in the middle ear. Most of these types of hearing loss can be treated medically and surgically. However, there is no medical treatment for an AB gap in sensorineural hearing loss and hearing loss can worsen gradually or suddenly. In addition, many studies have reported that head trauma makes hearing loss even more serious. Therefore, in order to differentiate between conductive hearing losses, it is important to check whether or not there is an enlarged vestibular aqueduct by means of temporal bone computerized tomography and/or magnetic resonance imaging.

• Journal of Audiology & Otology
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• v.25 no.3
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• pp.159-162
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• 2021

Temporal bone trauma can cause hearing loss and in case of prolonged conductive hearing loss, traumatic ossicular injury should be considered. Separation of the incudostapedial joint is the most common lesion, and stapediovestibular dislocation is relatively rare but can easily cause perilymphatic fistula. Here, we report a very rare case of external stapediovestibular dislocation after trauma, ending up with successful surgical outcome. A 27-year-old man with non-progressive hearing loss on the right side since childhood visited the clinic. Audiogram showed a conductive hearing loss with air-bone gap of 55 dB on the right side. Temporal bone CT revealed the disruption of ossicular chain. An exploratory tympanotomy identified multiple ossicular disruptions including external stapediovestibular dislocation with shiny fibrous membrane sealing the oval window. Ossicular chain reconstruction was performed using the total ossicular replacement prosthesis of titanium. A postoperative audiogram showed a recovery of air-bone gap less than 10 dB. To the best of our knowledge, this is the first case of external long-standing stapediovestibular dislocation, with oval window completely sealed with fibrous membrane, ending up with successful hearing recovery by surgery. This case would help dealing with such condition which can be encountered in the clinic.

• Korean Journal of Audiology
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• v.25 no.3
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• pp.159-162
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• 2021

Temporal bone trauma can cause hearing loss and in case of prolonged conductive hearing loss, traumatic ossicular injury should be considered. Separation of the incudostapedial joint is the most common lesion, and stapediovestibular dislocation is relatively rare but can easily cause perilymphatic fistula. Here, we report a very rare case of external stapediovestibular dislocation after trauma, ending up with successful surgical outcome. A 27-year-old man with non-progressive hearing loss on the right side since childhood visited the clinic. Audiogram showed a conductive hearing loss with air-bone gap of 55 dB on the right side. Temporal bone CT revealed the disruption of ossicular chain. An exploratory tympanotomy identified multiple ossicular disruptions including external stapediovestibular dislocation with shiny fibrous membrane sealing the oval window. Ossicular chain reconstruction was performed using the total ossicular replacement prosthesis of titanium. A postoperative audiogram showed a recovery of air-bone gap less than 10 dB. To the best of our knowledge, this is the first case of external long-standing stapediovestibular dislocation, with oval window completely sealed with fibrous membrane, ending up with successful hearing recovery by surgery. This case would help dealing with such condition which can be encountered in the clinic.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.1064-1069
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• 1994

In order to realize the function of human interface of telecommunications whose objective is to interchange useful information among persons, we developed a bone conduction telephone with which hearing impaired persons with conductive or noise-induced hearing loss and presbycusis can communicate with each other without any other additional devices such as hearing aids. The bone conduction telephone we developed has chatacteristics as follows : (i) a hearing impaired person and a normal hearing person can communicate by bone and air conduction hearings, respectively, using only this telephone set because, as its receiver, it uses a bone conduction vibrator with which we can realize such function with the voice coil and damper of a small speaker unit, the vibrating plate, etc., (ii) it has tone control function compensating hearing losses of hearing impaired persons according to their hearing loss/frequency chatacteristics. Using the tone control function together with a received volume control, it has the received volume range of 20dB in loudness rating; and (iii) it has the function of three emergency calls and a bell lamp as the visual display of a received call.

• Journal of Sensor Science and Technology
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• v.22 no.2
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• pp.150-155
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• 2013

Recently, various hearing aids are developed to overcome hearing loss. There are available hearing aids, such as air conduction hearing aid, implantable middle ear hearing aid and so on. But air conduction hearing aid is inconvenience caused by howling, and ossicle chain driving type implantable middle ear hearing aid has some week point due to problem of possible nercobiosis of coupling spot along incus long process. In recent years, in order to improve these shortcomings round window (RW) driving hearing aid has been paying attention. In this paper, the physical cochlear model is proposed for a performance evaluation of the RW driving hearing aids of a transducer. In order to verify an experiment proposed on a performance of physical cochlear model, the transducer which has ossicles characteristics is used. By measuring and comparing the frequency characteristics of transducer with ossicles and human temporal bone, performance of physical cochlear model was verified. As from the result of experiment, it is expected that an implemented cochlear model is useful for evaluating characteristics of RW transducer.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.1021-1026
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• 2000

The thermal characteristics of high-speed air spindle system with built-in motor are studied. Experiment and finite element method analysis obtain temperature rise and temperature distribution of housing. For the analysis three-dimensional model is built and temperature rise and distribution in thermal steady state are computed for each rotational frequency. Generally. It is said that the heat generation of air bearing is negligible. But it is certain that the heat generation of air bearing can not be negligible especially in high-speed conditions Frequency response test for air spindle system is executed. In case that the heat generation of air spindle system is high, natural frequency of the system becomes lower when it reaches thermal steady-state and it means that the stiffness of air hearing becomes smaller due to the change of bearing clearance. It is shown that the temperature rise of all spindle system causes thermal expansion md induces the variation of hearing clearance. In consequence the st illness of air bearing becomes smaller.

• Journal of Preventive Medicine and Public Health
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• v.31 no.2 s.61
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• pp.285-292
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• 1998

To investigate the effect of smoking on the hearing threshold, 1,887 adult male workers who visited health care center during the period 1 January 1996 - 31 July 1997 were selected. Air-conduction hearing threshold level, diastolic blood pressure(DBP), total cholesterol, fasting blood sugar(FBS), hematocrit and obesity were measured. The data on age, occupation, and smoking were collected. Air-conduction hearing threshold in smoker was significantly higher than non-smoker in categories of 250, 500, 1000 and 4000 Hz(p<0.05). Mean values of PTA-low, PTA-mid, and PTA-high in smoker were also significantly higher than non-smoker(p<0.05). In multiple regression analysis, smoking is likely to play a significant role after controlling age, occupation, DBP, FBS, total cholesterol, hematocrit, and obesity(p<0.05). The hearing threshold was significantly increased with increasing age(p<0.05), the manufacturing worker may have higher hearing threshold(p<0.05). The higher hematocrit and the more obese, the higher hearing threshold(p<0.05). However, DBP, total cholesterol and FBS were not significantly related with hearing threshold level. In conclusion, smoking was significantly related with the hearing threshold level in adult men.

• Archives of Plastic Surgery
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• v.46 no.6
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• pp.525-534
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• 2019

Background In microtia patients with bilateral hearing impairment, hearing improvement is crucial for language development and performance. External auditory canal reconstruction (EACR) has been performed to improve hearing, but often results in complications. We performed transcutaneous bone conduction implant (TBCI) surgery in these patients. This study aimed to evaluate the safety and efficacy of TBCI surgery. Methods A retrospective review was performed of five patients who underwent auricular reconstruction and TBCI surgery and 12 patients who underwent EACR between March 2007 and August 2018. Hearing improvement was measured based on the air-bone gap values using pure-tone audiometry over a 6-week postoperative period. We reviewed other studies on hearing improvement using EACR and compared the findings with our results. The surgical techniques for TBCI were reviewed through case analyses. Results Postoperative hearing outcomes showed a significant improvement, with a mean gain of 34.1 dB in the TBCI cohort and 14.1 dB in the EACR cohort. Both gains were statistically significant; however, the TBCI cohort showed much larger gains. Only three of the 12 patients who underwent EACR achieved hearing gains of more than 20 dB, which is consistent with previous studies. All patients who underwent TBCI surgery demonstrated hearing gains of more than 20 dB and experienced no device-related complications. Conclusions TBCI is a safe and effective method of promoting hearing gains in microtia patients with bilateral hearing impairment. TBCI surgery provided better hearing outcomes than EACR and could be performed along with various auricular reconstruction techniques using virgin mastoid skin.