• Research in Vestibular Science
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• v.17 no.4
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• pp.170-174
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• 2018

Epidural anesthesia has significantly advanced in neuraxial anesthesia and analgesia. It is used for surgical anaesthesia and treatment of chronic pain. Hearing loss during or after epidural anesthesia is rare, and it is known to occur by the change of the intracranial pressure. Cerebrospinal fluid is connected with perilymph in the cochlear and vestibule that is important to hearing and balance. If the intracranial pressure is abruptly transferred to the inner ear, perilymph can be leak, that called perilymphatic fistula, dizziness, and hearing loss can occur suddenly. We report a 65-year-old woman who presented with acute onset dizziness and hearing loss during the epidural nerve block for back pain, wherein we speculated a possibility of perilymphatic fistula as the mechanism of hearing loss and dizziness. The mechanism of dizziness and hearing loss was suspected with perilymphatic fistula.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.3 no.1
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• pp.21-35
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• 1995

Nowadays aviation noise significantly affects a number of people over the world. This paper is mainly focused on the effect of temporary and permanent hearing loss of cockpit crew, flight attendants, passengers, persons in communities exposed to aircraft overflight. Also this paper describes the human hearing mechanism and the processes of temporary and permanent hearing loss. The results of research are presented and the potential for hearing loss in aviation noise environments evaluated. The Occupational Safety and Health Administration (OSHA) hearing protection criteria are also addressed.

• Safety and Health at Work
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• v.11 no.3
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• pp.249-261
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• 2020

Background: Hearing loss is one of the most prevalent worker health conditions worldwide. Although the effect of noise exposure on hearing is well researched, other workplace exposures may account for significant hearing loss. The aim of this review was to determine whether occupational hand-arm vibration exposure through use of power or pneumatic tools, independent of noise exposure, is associated with permanent hearing loss. Do workers suffer from hand-arm vibratione-induced hearing loss? Methods: Peer-reviewed articles published in English between 1981 and 2020 were identified through five online databases with five search keywords. Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, including online database search methodology, study selection, article exclusion, and assessment of potential study design confounders and biases, were followed. Results: Database searches retrieved 697 articles. Fifteen articles that reported 17 studies met the criteria for review. All but two studies revealed statistically significant associations between occupational exposure to hand-arm vibration and hearing loss. The majority of the study results revealed associations between hand-arm vibration and hearing loss, independent of potential age and noise confounders. Conclusion: Few studies have examined the association between occupational exposure to hand-arm vibration and hearing loss. Dose response data were limited as only one study measured vibration intensity and duration. Although the majority of studies identified statistically significant associations, causal relationships could not be determined. Further research using standardized and uniform measurement protocols is needed to confirm whether the association between occupational exposure to hand-arm vibration and permanent hearing loss is causal and the mechanism(s).

• Speech Sciences
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• v.5 no.1
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• pp.167-179
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• 1999

The hearing mechanism is a complicated system. Sound is generated by a source that sends out air pressure or power. The pressure or power makes the sound waves. These waves reach the eardrum, or tympanic membrane, which vibrates at a rate and magnitude proportional to the nature of the sound waves. The tympanic membrane transforms this vibration into the mechanical energy in the middle ear, which in turn converts it to the hydraulic energy in the fluid of the inner ear. The hydraulic energy stimulates the sensory cells of the inner ear which send neuroelectrical impulses to the central auditory nervous system. The passive perception of auditory information starts just here. The listener gives attention to the speech sound, differentiates the sound from background noise, and integrates his experience with similar sounds. The listener then puts all of these aspects of audition into the context of the moment to identify the nature of sound. This has a major role in human communication. This paper provides an overview of the nature and characteristics of sound, the structure and function of the auditory system, and the way in which sound is processed by the auditory system.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.3
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• pp.218-223
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• 2006

Sensorineural hearing loss is frequently found in patients with chronic renal failure (CRF). There have been many efforts to elucidate the etiologic factors of hearing loss in patients with CRF. However, there was not any clear identified cause of hearing loss. This study was undertaken to evaluate the activity of mitochondrial respiratory chain (MRC) in CRF patients with hearing impairment. To determine MRC activity, peripheral blood cells were obtained from CRF patients with hearing impairment receiving dialysis and normal subjects without any hearing problems. MRC activity of complex I and complex III was measured by the Trounces method. In MRC activities between the normal subjects group and CRF patients with hearing problems, the complex I and III activities of CRF patients with hearing problems were 63% and 85% compared with normal subjects (p<0.01). These results suggest that the activity of MRC may be implicated in the underlying mechanism of the hearing impairment in CRF patients, through mitochondrial DNA mutations at MRC complex I region with a decrement of MRC activity.

• Journal of Audiology & Otology
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• v.23 no.2
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• pp.63-68
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• 2019

Background and Objectives: To investigate the relationship between hearing impairment and alcohol drinking patterns in South Korean adults. Subjects and Methods: Data collection was performed by Korean National Health and Nutrition Survey from January 1 to December 31, 2012. Data analyses were performed from February 20 to March 3, 2018. Data from 3,860 adults 20 years of age or older without a history of malignancy or chronic otitis media in the Korean National Health and Nutrition Survey 2012 database who participated in the health questionnaires, and who had available results from otologic examinations that included pure tone audiogram, were included. Pure-tone average hearing thresholds were calculated at 500, 1,000, 2,000, and 4,000 Hz. Hearing loss was defined as a pure-tone average >40 dB in one or both ears. The Alcohol Use Disorder Identification Test was used to evaluate drinking statuses of subjects. Data were analyzed using the complex-sample χ²-test of independence and a complex-sample logistic regression analysis. Results: Of the 29,954,319 individuals in the weighted cross-sectional study population, 15,106,040 (50.4%) were men and 14,848,098 (49.6%) were women. A total of 8.1% of men and 7% of women had hearing impairment. The degrees of drinking with appropriate, risky, and hazardous drinking habits were 58.2, 32.1, and 9.7% among men; and 76.4, 12.5, and 11.1% among women, respectively. Among men, the odds ratio of hearing loss increased by 2.506 times when comparing hazardous and appropriate drinking (confidence interval, 1.083 to 5.800, p=0.002). Moderate alcohol consumption (≤2 drinks per day) was not protective for hearing in either group. Conclusions: As hazardous drinking tends to coexist with hearing impairment in men, appropriate prevention and intervention strategies should be emphasized. A longitudinal study to investigate harmful drinking and the mechanism of hearing loss should be performed.

• Korean Journal of Audiology
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• v.23 no.2
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• pp.63-68
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• 2019

Background and Objectives: To investigate the relationship between hearing impairment and alcohol drinking patterns in South Korean adults. Subjects and Methods: Data collection was performed by Korean National Health and Nutrition Survey from January 1 to December 31, 2012. Data analyses were performed from February 20 to March 3, 2018. Data from 3,860 adults 20 years of age or older without a history of malignancy or chronic otitis media in the Korean National Health and Nutrition Survey 2012 database who participated in the health questionnaires, and who had available results from otologic examinations that included pure tone audiogram, were included. Pure-tone average hearing thresholds were calculated at 500, 1,000, 2,000, and 4,000 Hz. Hearing loss was defined as a pure-tone average >40 dB in one or both ears. The Alcohol Use Disorder Identification Test was used to evaluate drinking statuses of subjects. Data were analyzed using the complex-sample χ²-test of independence and a complex-sample logistic regression analysis. Results: Of the 29,954,319 individuals in the weighted cross-sectional study population, 15,106,040 (50.4%) were men and 14,848,098 (49.6%) were women. A total of 8.1% of men and 7% of women had hearing impairment. The degrees of drinking with appropriate, risky, and hazardous drinking habits were 58.2, 32.1, and 9.7% among men; and 76.4, 12.5, and 11.1% among women, respectively. Among men, the odds ratio of hearing loss increased by 2.506 times when comparing hazardous and appropriate drinking (confidence interval, 1.083 to 5.800, p=0.002). Moderate alcohol consumption (≤2 drinks per day) was not protective for hearing in either group. Conclusions: As hazardous drinking tends to coexist with hearing impairment in men, appropriate prevention and intervention strategies should be emphasized. A longitudinal study to investigate harmful drinking and the mechanism of hearing loss should be performed.

• Journal of Ginseng Research
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• v.34 no.4
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• pp.336-341
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• 2010

One mechanism of inner ear damage by noise-induced hearing loss (NIHL) is the production of reactive oxygen species (ROS). Because Korean red ginseng (KRG) has an anti-ROS effect in various tissues, KRG may have a role in preventing NIHL. A window period exists in which ROS formations continue after noise exposure, and further damage can be prevented by antioxidants. In this study, we aimed to investigate the effects of KRG after exposure to noise. KRG (200 mg/kg) was fed to mice for 3 days after noise exposure. The change in hearing level was analyzed by measuring the auditory brainstem response. To induce a temporary threshold shift (TTS) of hearing, mice were exposed to 110 dB white noise for 3 hours. Fast recovery of hearing was observed in mice fed KRG 1 hour and 1 day after noise exposure for 3 days. The expression of 8-oxoguanine was not observed in the inner ears of mice fed KRG 1 hour after noise exposure, but was evident in the stria vascularis of mice in the control group (noise exposure only). From this study, we conclude that KRG acted as an effective inhibitor of NIHL in TTS cases.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.8
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• pp.338-348
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• 2001

A hybrid self-hearing motor, which Is a functional combination of general permanent magnet (PM) motor and hybrid active magnetic bearing(AMB), was proposed a few years ago. In this paper the hybrid self-bearing motor is modified to a disk type, in which one of two magnetic hearings was substituted for a thin yoke to make the system more compact. An outer rotors in this self-hearing motor is actively controlled only in two radial directions while the ocher motions are passively salable owing to the disk-type structure. Main advantages of the proposed self-hearing motor are simple control mechanism, low power consumption and smart structure. Mathematical model for the magnetic force Is built wish consideration of the radial displacement of the rotor. The model helps us not only to design a levitation controller but also to expect the system performance. Some experimental results show good capability and feasibility of the Proposed self-bearing motor.

• The Journal of Korean Association of Computer Education
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• v.7 no.4
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• pp.93-102
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• 2004

For children with hearing impairment, unlike the children without hearing impairment who can reconstruct their languages through the process of hearing and uttering, the inherent mechanism for language acquisition do not operate due to the loss of hearing ability. Therefore, to help hearing-impaired children develop their language ability, web-based language learning system should be constructed depending on the special qualities which the children possess in language learning process. When the system is being designed, it is necessary that words or expressions describing actions or situations be animated and that active situation-based language learning system be constructed to help them develop their power of observation. Moreover, the system needs to be developed through the use of alternative thinking strategy, antonyms, and contrastive words, and emphasis on facial expressions. This paper presents web-based language learning system which is suitable for hearing-impaired children in the way to reduce the grammatical errors they make and to improve their language learning.