• Journal of Preventive Medicine and Public Health
• /
• v.32 no.1
• /
• pp.17-29
• /
• 1999

Objectives. This study was carried out to analyze the hearingthreshold levels and relating factors of 1,048 workers with noiseinduced hearing loss$(D_1)$. Methods. We analyzed the hearing-threshold levels and relating factors of 1,048 workers with noise-induced hearing loss$(D_1)$ examined by the summary reports of specific health examination results of industries and personal reports of specific health examination results reported by 58 specific health examination institutes and 8 secondary pneumoconiosis examination institutes in 1996. Results. Among 1,048 workers at 510 workplaces, male workers were 1,009 (96.3%) and female workers were 39 (3.7%). The mean ages of workers initially exposed to noise and at present were 28.7 and 47.2, respectively. The duration of total exposure was 16.5 years. Average hearing-threshold levels analyzed by three-divided classification of the study subjects were 43.7dB(Lt) and 42.6dB(Rt). Those analyzed by six-divided classification were 50.5dB(Lt) and 48.6d8(Rt). Among workers with noise-induced shearing loss$(D_1)$, 16.3% was unilateral hearing loss and 84.6% was classified to compensation case. 8.8%(Rt) and 10.2%(Lt) of them were suspected to be conductive hearing loss by differences of air-bone hearing-threshold levels. Hearing-threshold levels of workers in manufacturing industry were significantly increased during the short exposure compared with the levels in mining industry. Among manufacturing industries, hearing-threshold levels of workers in trailer and other transportation equipment manufacturing industry were significantly increased. Age and duration of total noise exposure were not significantly related to the average hearing-threshold levels analyzed by three-divided classification. Hearing-threshold levels of female workers were significantly increased during the short exposure compared with those of male workers. Hearing-threshold levels of workers at the high risk group, ages of 20s, 30s and total exposure duration of less than 10 years, were not significantly increased compared with those of the other groups. However, they were exposed at young ages. The 3 leading industries of workers at high risk group were trailer and other transportation equipment manufacturing, automobile manufacturing and assemble-metal manufacturing industries. Conclusions. This study was the first nationwide analysis of the hearing-threshold levels and relating factors of workers with noise. induced hearing loss$(D_1)$. We found the differences of the real number by the statistics of the department of labour and the expected number of worker' s compensations for occupationally-induced hearing loss estimated by this study. According to the results of this study, we should carefully examine the methods to narrow this difference.

• Journal of Preventive Medicine and Public Health
• /
• v.24 no.1 s.33
• /
• pp.86-92
• /
• 1991

To test if exposure history to rifle fire or cannonade training during military duty can induce hearing loss, history of personal military service and histroy of gunshot exposure were asked to 228 male college students with self -administrative questionnaire. Otoscopic examination and Rinne's test were performed if any abnormal finding was detected by pure-tone audiometry. Average hearing threshold levels of 500 Hz, 1,000 Hz, 2,000 Hz, 4,000 Hz and threshold levels at 4,000 Hz were calculated for 112 students who were remained after exclusion of cases with history of ear disease, of ototoxic drug administration, and of neuropsychiatric disease, and mean of those were compared between group of students who have completed military duty (completed group) and group of those who have not (not-completed group), and between group exposed (exposed group) and group unexposed to gunshot sound (unexposed group). Mean of average hearing threshold level and mean of threshold levels at 4,000 Hz of completed group and those of exposed group were higher than those of not-completed group and unexposed group, respectively. Proportion of cases that average threshold level was greater than 40 dB or threshold levels at 4,000 Hz was greater than 50 dB were higher also in completed group and exposed group than in duty not-completed group and unexposed group, respectively Multiple linear regression analysis including age, duration of military service, degree of gunshot sound exposure as independant variables and average hearing threshold level as dependant variable, was performed in order to estimate the effect of age on hearing, and any considerable effect of age on hearing could not be found. In conclusion, hearing impairment can be induced by rifle fire or cannonade training.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.21 no.3
• /
• pp.162-167
• /
• 2011

To identify the relationship between types of job classification (typical and atypical) and the levels of recognition of noise and the hearing threshold shift, a total of 457 workers in a cosmetic company were studied utilizing a questionnaire and the audiometric hearing test. The results were analyzed by factor analysis, t-test, and general linear model, as appropriate. The results showed that atypical workers had higher level of noise recognition but had lower levels of hearing ability, noise exposure, and the knowledge on hearing loss prevention, compared with those of typical workers. The high noise level group of typical workers showed higher threshold shift levels than that of atypical workers. Significant differences were found at 4 kHz for both ears and in right ear only for hearing threshold shift after adjusting age.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.23 no.3
• /
• pp.275-282
• /
• 2016

Purpose: This study was done to examine the relationship between nursing students' hearing levels and accuracy of blood pressure (BP) measurements. Methods: Participants were 107 students who had finished their fundamental nursing practice and clinical practicum and who used earphones. Data were collected from October 13 to November 30, 2014 and from April 30 to May 19, 2015. Students' hearing thresholds were examined using an audiometer. Students were assigned to take two BP measurements on BP measurement training simulators, but only the second measurement was used for analysis. Results: All nursing students' hearing levels were within normal range, and there was no significant difference found among the settings for diastolic blood pressure. However, there were significant differences between low systolic blood pressure (SBP) (below 120mmHg) and high SBP (over 140mmHg) (z=9.02, p=.011). Measurement error in SBP showed a positive correlation with hearing threshold in the right ear at frequencies of 1000Hz and 500Hz. Conclusion: Findings indicate that BP measurement error is correlated with hearing threshold at some frequencies. To reduce measurement error, nursing students should be provided with health education about hearing and to improve training for students, further studies need to examine other factors influencing BP measurement error.

• Journal of Preventive Medicine and Public Health
• /
• v.7 no.1
• /
• pp.177-183
• /
• 1974

It is generally recognized that the environmental noise of the various working places thought to be the cause of hearing disturbance. This survey was carried out to evaluate the prevalence of noise-induced occupational bearing loss among the weavers of 39 textile industries in Taegu, Korea. For this survey, 432 male workers and 2,023 female workers were examined their hearing acuity by Individual pure tone threshold determination test(air conduction), from November, 1972, to January, 1973. Main findings were as follows : 1. The mean of noise intensity of the 54 weaving rooms was, in over all, $95.6{\pm}4.2dB\;(A),\;95.9{\pm}4.0dB\;(B)\;and\;96.2{\pm}3.9dB\;(C)$. 2. The mean hearing threshold levels by service years in the 4,000 Hz were intensively increased from 1st to 3rd year and slightly decreased. than that of 3rd year, from after 3rd to 5th year, after 5th year that increased slightly. 3. The mean hearing threshold levels by frequencies were highest in the 4,000 Hz(male: $25.0{\pm}11.3dB$, female: $22.0{\pm}10.2dB$) and followed by 6,000, 8,000 and 3,000 Hz. 4. The mean hearing threshold level of the 6,000 Hz (male: 17.0 dB. female: 17.9dB) was higher than that of 4,000Hz (male: 16.4 dB, female: 17.1dB) in tile 1st service year. 5. The mean hearing loss of examinees was $16.2{\pm}8.0dB$ in male and $15.4{\pm}7.8dB$ in female.

• Speech Sciences
• /
• v.12 no.4
• /
• pp.197-202
• /
• 2005

The cochlear implantation(CI) as an useful tool for aural rehabilitation in bilateral severe to profound hearing impairment. However, CI prefer to usually one ear in spite of bilateral hearing impaired. because of the various characteristics of hearing loss, the hearing conservation for the future possibility, and socioeconomic condition of hearing impaired person and their families. The unilateral CI has limitations such as a directional loss, a difficult speech understanding in noise and a neural plasticity. These limitations will be overcome by hearing aid(HA) which is familiar with hearing impairer. but HA fitting for bimodal-binaural hearing are difficult because the difference output characteristic of HA and CI. This study will be confirm realities of use of HA in unilateral cochlear implantee. For this goal, 25(m:f=10:15) child participated who are used to HA for 1 to 17 months. We had telephone interviews with their mother about use of HA, change of auditory performance and own voice. As the results, hearing threshold levels of unimplanted ear, the use of a appropriate HA, implanted and aided hearing threshold level(HTL) are must be considered for successful biomodal-binaural hearing. Especially, implanted and aided HTL should be very useful parameter for a prediction of HA effect and a criterion of selection for bilateral cochlear implantation.

• Journal of the Ergonomics Society of Korea
• /
• v.15 no.1
• /
• pp.79-90
• /
• 1996

A research project was conducted to assess the levels of noise exposed to "Noraebang" users and potential hazards to noise-induced hearing loss due to commercial Noraebang noise. A two-way, mixed-factors factorial design was employed for the experiment using independent variables of "noise source" (no- singer, 1-singer, and 2-singer conditions) and "music type" (Trot, Ballad, and Rock music) with 18 normal hearing subjects. Each singer group sang 5 popular songs of each music type in each signing condition, whereas background music was just played for the no-singer condition. For each music played/sung, equivalent continuous sound pressure levels and maximum sound pressure levels were measured for data analysis purposes. Pure-tone audiometry was applied for measuring subjects' hearing threshold levels before and after exposure to Noraebgang noise. The statistical analyses indicate that average continuous noise levels due to Noraebang leisure environment were very serious, especially when two people were singing (higher than 95 dBA). Furthermore, maximum noise levels often exceeded the OSHA's non-premissible 115 dBA level. Worse yet, hearing loss assessment implies that Noraebang facilities may pose a serious threat to noise-induced hearing loss, based on 6-8 dB loss at 125 Hz and 8 dB loss at 4000 Hz after about 1-hour Noraebang noise exposure.

• Journal of Preventive Medicine and Public Health
• /
• v.17 no.1
• /
• pp.57-63
• /
• 1984

To assess the hearing conservation by the hearing protection devices in the field, 1,237 healthy female weavers of 16 to 24 year old were surveyed from April 1982 to January 1983. By reviewing the charts, their working durations, hearing threshold shift levels and whether wearing the ear plugs or not were checked. The hearing threshold levels were measured at 4,000Hz by audiometry AA-30A, RION Japan. They were divided into two groups: an experimental group with ear plug and the control group without it. The threshold shift level above 40dB in controls was 44.6% in left and 40.9% in right ear and that in experimental group 8.0% in left and 6.6% in right ear. The distribution of threshold shift levels between control and experimental group was significantly different in both ears, but that between left and right ear not significantly different in both groups. The longer the working durations were, the more the proportion of high threshold shift levels was and the larger the differences in the proportion of above 40dB between both groups were.

• The Journal of the Acoustical Society of Korea
• /
• v.24 no.6
• /
• pp.353-357
• /
• 2005

Declining auditory performance with advanced age is a well known and common problem that is becoming more Prevalent due to the increasing number of elderly people in our society. We introduce a novel ARCISM (Audiogram Result Computer Input. Save & Management software) data management program which enables the assessment of the risk of past history of hearing impairment on the basis of known risk factors. This study investigates the reference levels of pure tone hearing threshold of normal aging in Korean and the difference between fenders. The subjects were carefully selected by questionnaire and absence of any history of otologic infection, noise exposure. and ototoxic drug among 1603 subjects. who visited Health Promotion Center in Daegu Fatima Hospital for one year. The results show (1) hearing sensitivity declines with age. (2) higher frequency shows steeper slope of hearing declines than lower frequency. and (3) there were more hearing loss at 4 and 8 kHz in men than in women. Due to the ARCISM program. it was possible to manage huge data of hearing results and to obtain the reference level of a9e-related hearing declines. Furthermore, we expect that the results of this study can be the fundamental data for hearing rehabilitation for the elderly and for developing suitable hearing aids for Korean.

• Progress in Medical Physics
• /
• v.9 no.4
• /
• pp.217-225
• /
• 1998

In this paper, the analysis of the relation between noise induced hearing loss and noise exposure is described for the A-weighted noise levels and exposure duration. The hearing loss and sensitivity threshold shift is investigated by changing the various parameters such as the effects of aging and noise exposure. Total hearing loss is proportional to a function of exposure level based upon the integral of pressure with time. If the noise exposure term is large so that the presbycusis may be neglected, the hearing loss due to aging and noise exposure becomes the noise induced hearing loss. It is shown that exposure to excessive noise can cause temporary loss of hearing that may become permanent if the exposure is prolonged or intense. An audiogram taken from a person suffering from noise induced hearing loss will usually show the greatest loss of hearing sensitivity in the 4kHz region, which is typically the region most sensitive to damage resulting from many types of industrial noise.