• 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.

• Investigative Magnetic Resonance Imaging
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• v.9 no.2
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• pp.134-139
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• 2005

Purpose : To evaluate the usefulness of acoustic noise attenuator on auditory fMRI examination. Materials and methods : The acoustic noise attenuator consists of mask, earmuff and silicon earplug. The soft polyurethane sheet and polyurethane form , which has a good soundproof characteristic were used for mask and earmuff. Auditory fMRI experiments of 500 Hz pure tone stimulation were performed in three different cases; first all of mask, earmuff and earplug, secondly earmuff and earplug only and finally without attenuator in 4 normal hearing volunteers. For data acquisition, BOLD MR imaging technique was employed at a 1.5T MR scanner equipped with high performance gradient system. The raw data were analyzed using a SPM-99 analysis software and the activation maps were obtained. Results : In case of all items of acoustic attenuator used, the results revealed that activation was focused on primary auditory area. When only earmuff and earplug were used, the results showed that the activation spread over primary auditory and secondary associative areas. Last, when no device used, only weak activation was observed on the right auditory cortex. Conclusion : It is expected that the acoustic noise attenuator, which consists of earplugs, earmuffs and mask, is a very useful device in auditory fMRI study.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.2
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• pp.153-159
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• 2007

Usually equal noise exposure is considered to cause symmetrical hearing loss, but some screening audiometries of employees who were exposed to noise showed asymmetry. Therefore, this study was carried out to evaluate the distribution of asymmetrical hearing loss and the difference of air conduction level between left and right ear at the different frequencies (500, 1,000, 2,000, 3,000, 4,000, 6,000 Hz). Study subjects were 326 male employees who had participated in the noise-specific health examination from May to October, 2002. They were evaluated by otoscopic examination, pure tone audiometry and tympanometry. In all frequencies, hearing threshold level of left ear was worse than right ear. The mean interaural threshold differences between two ears were 0.83 dB at 500 Hz, 1.18 dB at 2,000 Hz, 2.29 dB at 3,000 Hz, 2.18 dB at 4,000 Hz, and statistically significant (p<0.05). The hearing loss of left ear was greater than right ear in occupationally noise-exposed workers. It is believed that left ear was more susceptible to noise damage than right ear

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.4
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• pp.269-275
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• 2003

In this paper, We examined auditory threshold and critical ratio of amberjack seriola dumerili, in the Jeju Island coastal waters, to find out hearing ability of the fish. The auditory threshold level, critical ratio and hearing index of amberjack were determinded by conditioning method using a sound coupled with electric shock in the condition of ambient noise or white noise in an experimental water tank. The audio-signals of pure tone and electric shock were from 80 HZ to 800 Hz and DC 7 V, respectively. Values for the critical ratios were calculated in terms of the masked thresholds using the noise projected to stable spectrum levels at all measurement frequencies of background noise. Masking noises were in the spectrum level range of 65 dB∼75 dB $(re 1{\mu}Pa\sqrt{Hz})$. The auditory thresholds of amberjack within the test the frequencies were most sensitive at 300HZ as 94.5 dB. The critical ratios of fishes ranged from 36.4 to 52.8 dB. The noise spectrum level that started masking was about 58∼72 dB within frequencies.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1977.06a
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• pp.6.1-6
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• 1977

Among the various audiometric test batteries, pure tone and speech audiometry was carried as routine. During the past 20 years, there have been works on speech word list for Korean language. As a preliminary work for standardization of Korean speech word list, the authors are intended to study on the factors of test methods with these proposal speech word lists. Now, authors has studied as followings methods and materials and the results were obtained as followings. A. Materials and Methods a. Word List 1. Paik Chun Kee (Paik) 2. Soh Jin Myoung (Soh) 3. Cynn Kyu Shik (Cynn) 4. Lee Jong Dam (Lee) 5. Hahm Tae Young (Hahm) b. Test Method 1. ascending 2. descending c. Test Material 1. live voice 2. Recorded male voice 3. Recorded female voice B. Results 1. Score of ascending method was better result than descending method. 2. Speech reception threshold and discrimination score were better in recorded female voice, live voice and recorded male voice in that order. 3. Speech reception thresholds among tested word lists were Hahm, Lee, Soh, Cynn and Paik in that order. 4. Discrimination score was highest with Cynn and Lee, Soh, Hahm, Paik in that order.

• Journal of Preventive Medicine and Public Health
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• v.30 no.2 s.57
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• pp.356-368
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• 1997

In effort to determine whether aircraft noise can have health effects such as hearing loss, hypertension and psychological stress, a total of 111 male professors and administrative officers working a college near a military airport in Korea(exposed group) and a total of 168 males and 112 females matched by age groups(control groups) were analyzed. Personal noise exposure and indoor and outdoor sound level of jet aircraft noise were measured at the exposed are3. And pure tone, air conduction test and measurement of blood pressure were given to the exposed(males) and matched control groups (males and females). BEPSI(Brief Encounter Psychological Instrument) and psychological response to aircraft noise were examined for the exposed group. The noise dosimetry results revealed time-weighted averages(TWAs) that ranged from 61 to 68 dBA. However the levels encountered during taking off jet airplanes reached 126 dBA for two half minutes time period. Th, audiometric, test showed that mean values of HTL(hearing threshold level) in exposed group at every frequency(500, 1,000, 2,000, 4,000, and 8,000 Hz were much lower than them of male and female control groups. And in old age groups, interaction of age and noise was observed at 8,000 Hz in both ears(p<0.05). Conclusively, aircraft noise does not appear to induce hearing loss directly in high frequency, but may decreased hearing threshold level by interaction of aging process and noise exposure. However, difference of mean values of exposed and control groups on blood pressure was not significantly. In psychological test, annoyance was the most severe psychological response to noise in exposed group, but mean value of BEPSI was not correlated with job duration in exposed group.

• Journal of Preventive Medicine and Public Health
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• v.39 no.2
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• pp.159-164
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• 2006

Objectives : This study was conducted to evaluate the effects of the personal stereo system on the hearing in adolescents. Methods : A total of 68 adolescents(age: 13-18 years) who visited the ENT Department at a University Hospital in Daegu were personally interviewed. The questionnaires were about general characteristics of the subjects, the time of personal stereo system use (year, hour) and place. Cumulative exposure to the personal stereo system was calculated by the product of the total years and the daily hours of their use. Pure tone audiometry was performed and the hearing threshold was measured at 500, 1000, 2000, 4000 and 8000 Hz. Results : The average time of using a personal stereo system a day was about 3 hours and 75% of the subjects used a personal stereo system for 2-5 years. The elevation of threshold was more prominent in the subjects who used personal stereo systems for 4 years and more compared with those subjects who used them for 3 years and under. The elevation of hearing threshold was also more prominent in the subjects who used personal stereo systems for 4 hours and more a day compared with those subjects who used personal stereo systems for 3 hours and under a day. The elevation of hearing threshold was more prominent in the subjects who used personal stereo systems for 13 hour. years and more compared to the subjects who used them 12 hour. years and under. Conclusions : These results suggest that the elevation of hearing threshold can happen to adolescents who used personal stereo systems for a long time. In order to prevent hearing loss, we need to teach adolescents appropriate usage of the personal stereo system and hearing tests should be included in the periodic school-based physical examination for the adolescents.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1976.06a
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• pp.85.1-85
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• 1976

Audiological evaluation was performed for 184 female weavers (351 ears), who were 18~25 years old and have been working under exposure of 103~105 ㏈a of machinary noise. With the duration of employment, they were divided into five groups; under 1 year, 1~2 years, 2~3 years, 3~4 years and over 4 years. The following results were obtained: 1. The incidence ;of noise induced hearing loss was 39.7% (36.2% of ears) and rapidly increased during first 1~2 years. 2. The average maximum hearing loss on the pure tone audiograms appeared at 4,000Hz with .about 40 ㏈ of hearing level. The average hearing level at high frequencies(3,000Hz~8,000Hz) showed below 25㏈ of hearing level in all groups and had the tendency to increase slightly with the duration of working, but the most of hearing losses developed during first one year except at 8,000Hz. 3. The average hearing level at speech frequencies was within normal range but the cases of hearing level over 25 ㏈ at 2,000Hz was 27.1%. 4. The cases with maximum hearing loss at 4,000Hz were 72.7%, but the cases of maximum hearing loss at the other frequencies (3,000Hz, 6,000Hz .and 8,000Hz) were also observed and they increased slightly in numbers with the duration of working. The noise induced hearing loss under the exposure of 103~105㏈a for 5 years, seemed to develope during first 1~2 years and there after slightly .increased hearing loss was showed but no remarkable changes were observed.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• v.60 no.8
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• pp.390-395
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• 2017

Background and Objectives With increasing frequency of car accidents, patients of dizziness caused by car accidents are also increasing. Various types of dizziness or vertigo can occur from car accidents depending on different injury mechanisms. Since accurate diagnosis is important for providing proper treatments, we evaluated clinical characteristics related to vestibular function of patients with dizziness caused car accidents. Subjects and Method In this retrospective case review study that runs from January 2011 to March 2013, a total of 82 patients with dizziness following car accident were enrolled consecutively. We analyzed the final diagnosis of dizziness according to different mechanisms of injury during car accident through clinical record review. Patients who developed dizziness within one month of car accident were included, excluding those who had temporal bone fracture and previous history of dizziness. Results Of the different types observed, 36.6% was head injury, 24.4% whiplash injury, 3.7% complex injury, 2.4% others and the rest was unknown. In the final diagnosis, the different types included 36.6% benign paroxysmal positional vertigo (BPPV), 23.2% unclassifiable dizziness, 18.3% cervical vertigo, 7.3% labyrinthine concussion, 3.7% BPPV with labyrinthine concussion and the rest was others. Of the different types of dizziness symptoms, 58.5% was headache, 45.1% was audiologic symptoms, and others included earfullness, tinnitus and hearing disturbance. Tinitogram and pure tone audiogram results show that 2.9% (27 people) of patients have tinnitus and 7.3% (6 people) have hearing disturbance. Conclusion An accurate diagnosis and timely management would be very important in forming a proper approach for post traumatic vertigo patients.

• Korean Journal of Audiology
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• v.24 no.1
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• pp.29-34
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• 2020

Background and Objectives: Bilateral microphones with contralateral routing of signal (BiCROS) hearing aid is an option for hearing rehabilitation in individuals with asymmetric sensorineural hearing loss (ASNHL). The clinical factors influencing the trial and purchase of BiCROS were investigated. Subjects and Methods: We reviewed the medical records of 78 patients with ASNHL who were recommended to use BiCROS and analyzed the demographic and audiological factors influencing the trial and purchase of BiCROS. Results: Among the 78 patients, 52 (66.7%) availed of the free BiCROS trial and 21 (26.9%) purchased BiCROS. The mean pure tone audiometry (PTA) air conduction (AC) threshold of the better- and worse-hearing ears were 44.2±12.8 dB and 90.7±22.5 dB HL, respectively. The decision for trial or purchase of BiCROS was not influenced by age, sex, duration of hearing loss of the worse-hearing ear, or PTA AC threshold or speech discrimination score of both ears. The first and third quartiles of the PTA AC thresholds for the better-hearing ear of BiCROS buyers were 38.75 dB and 53.75 dB HL, respectively. The counterpart values for the worse-hearing ear were 72.50 dB and 118.75 dB HL, respectively. Conclusions: The clinical factors analyzed in this study were found to be irrelevant to the trial and purchase of BiCROS in patients with ASNHL. Nevertheless, the distribution range of the auditory thresholds of the subjects using BiCROS can be a useful basis for the counseling of patients with ASNHL and selection of candidates for BiCROS use.