BACKGROUND AND OBJECTIVES: A rotation chair test has been used to evaluate the function of the horizontal semicircular canals. Currently, two chair systems according to the presence of cylindrical darkroom are used in a clinic setting. However, it has not been thoroughly investigated whether one system is superior to the other system or not. In this study, we aimed to compare test outcomes and subject convenience between two systems. SUBJECTS AND METHODS: Twenty subjects with no history of otologic disease were enrolled. Subjects were tested with two systems: system [A] with a cylindrical chamber and system [B] with no chamber. The results of sinusoidal harmonic acceleration (SHA), step velocity (SV), and visual fixation (VFX) tests were compared between the systems. Subject convenience was assessed with a questionnaire survey and results were compared between the systems. RESULTS: There were no significant differences in gain or asymmetry in SHA test between the systems. However, the phase of system [A] was significantly lower than that of system [B] at 0.16 Hz. There was no significant difference between the systems in directional preponderance (DP) gain or DP time constant. Regarding the VFX test, gain was higher in system [A] than system [B]. Subjects reported less stuffiness and less anxiety with system [B] than system [A], while preferring the system [A] goggles. CONCLUSIONS: A rotation chair system without a darkroom can provide a more comfortable experience for subjects in terms of stuffiness and anxiety, while showing comparable results in SHA and SV tests with a darkroom system.
Acceleration ; Anxiety ; Ear Diseases ; Eye Protective Devices ; Semicircular Canals

BACKGROUND: The aim of this study was to evaluate the awareness of occupational hazards and personal protective equipment use among dental hygienists (DHs).METHODS: A total of 271 self-administered questionnaires were obtained from 280 DHs working at dental hospitals or clinics in Daegu and Gyeongsangbuk-do, Korea.RESULTS: The occupational hazards included work involving dust (94.1%), volatile substances (86.0%), noise (97.0%), and light-curing units (96.7%). The proportion of dental hygiene tasks that participants perceived as harmful were 42.4%, 51.7%, 9.2%, and 31.4% in the same order as above. The proportion of participants who used dust-proof masks during work involving dust was 1.1%. Those who wore gas-proof masks and gloves for work using volatile substances were 0.7% and 31.2%, respectively. Participants who used goggles for work involving light-curing units were 31.0%. None of the participants used ear plugs for work involving noise. A total of 22.9% of the participants recognized the Material Safety Data Sheet, while 79.7% had never been educated about harmful work environments.CONCLUSION: When compared to exposure status and perception of occupational hazards, the level of protective equipment use was very low. Extra measures to increase DHs’ use of personal protective equipment are necessary.
Daegu ; Dental Hygienists ; Dust ; Ear ; Eye Protective Devices ; Gyeongsangbuk-do ; Humans ; Korea ; Masks ; Material Safety Data Sheets ; Noise ; Occupations ; Oral Hygiene ; Personal Protective Equipment

OBJECTIVE: To compare effectiveness on correcting cranial and ear asymmetry between helmet therapy and counter positioning for deformational plagiocephaly (DP). METHODS: Retrospective data of children diagnosed with DP who visited our clinic from November 2010 to October 2012 were reviewed. Subjects < or =10 months of age who showed > or =10 mm of diagonal difference were included for analysis. For DP treatment, information on both helmet therapy and counter positioning was given and either of the two was chosen by each family. Head circumference, cranial asymmetry measurements including diagonal difference, cranial vault asymmetry index, radial symmetry index, and ear shift were obtained by 3-dimensional head-surface laser scan at the time of initiation and termination of therapy. RESULTS: Twenty-seven subjects were included: 21 had helmet therapy and 6 underwent counter positioning. There was no significant difference of baseline characteristics, head circumferences and cranial asymmetry measurements at the initiation of therapy. The mean duration of therapy was 4.30+/-1.27 months in the helmet therapy group and 4.08+/-0.95 months in the counter positioning group (p=0.770). While cranial asymmetry measurements improved in both groups, significantly more improvement was observed with helmet therapy. There was no significant difference of the head circumference growth between the two groups at the end of therapy. CONCLUSION: Helmet therapy resulted in more favorable outcomes in correcting cranial and ear asymmetry than counter positioning on moderate to severe DP without compromising head growth.
Cephalometry ; Child ; Ear ; Facial Asymmetry ; Head ; Head Protective Devices* ; Humans ; Patient Positioning ; Plagiocephaly, Nonsynostotic* ; Retrospective Studies

OBJECTIVE: To identify the effect of the 'disability prevention program' for elementary school students. METHOD: Our disability prevention program was a 60 minutes program composed of watching an education video for disability prevention and having a conversation with disabled speakers in wheelchairs. A questionnaire to measure the effect of the education was administered among 5,315 students in the 4th to 6th grades. The questionnaire was administered at 7 days before and after education. The questionnaire was to measure the changes in self-efficacy and in confidence to follow safety regulation. Also the questions on satisfaction about program were asked. RESULTS: The result showed that only 9.7% of bicycle owners, 18.9% of inline skate owners wore helmets, 9.3% of quick board (or skateboard) owners wore helmets, and only 47.6% of students fastened seat-belts in a car. After the program was conducted, there were significant improvements in self-efficacy and practice-confidence to wear protective device and to fasten seat belt in a car (p<0.01). The most impressive part of the program for students was 'conversation with disabled speaker' and the next was 'watching the video'. After program was conducted, 51.5% of students answered "I will keep safety regulations in mind and practice it" and 10.1% of students answered "I could learn a better understanding of the disabled and I also want to help them". CONCLUSION: The 'disability prevention program with disabled speakers in wheelchair' was effective in improving the self-efficacy and practice-confidence for safety regulation.
Disabled Persons ; Head Protective Devices ; Humans ; Protective Devices ; Surveys and Questionnaires ; Seat Belts ; Self Efficacy ; Social Control, Formal ; Wheelchairs

BACKGROUND AND OBJECTIVES: The ability to localize a sound source is one of the binaural hearing benefits in a horizontal plane based on interaural time difference and interaural intensity difference. Unilateral or bilateral asymmetric hearing loss will affect binaural hearing and lead to sound locating errors. In this cross sectional analytical descriptive study, the localization error was investigated when participants turned their heads to the sound source with closed eyes and after simulating unilateral hearing loss by placing earplugs inside the right ear canal. SUBJECTS AND METHODS: This cross sectional analytical descriptive study was carried out on 30 right-handed adults, 22 female and 8 male (average: 25 years, standard deviation: 3.16). They were selected with the available random access method. Horizontal localization was evaluated with five speakers located at 0, ±30, and ±60 degree azimuths at a 1-meter distance from the examinee. Narrow-band noise signals were delivered at 35 dB SL in two “without earplug” and “with earplug” situations and the results were compared. The study was performed between September and December 2016 in Tehran, Iran. RESULTS: Significant differences were observed in localization errors between the “with earplug” and “without earplug” situations. The localization differences were greater for left-side speakers (-30 and -60 degrees) compared with right-side speakers (+30 and +60 degrees). The differences were more apparent at 4,000 and 6,000 Hz, which confirmed the effect of unilateral simulated hearing loss on interaural latency differences. CONCLUSIONS: Simulating hearing loss by using an earplug in one ear (right) increased localization errors at all frequencies. The errors increased at higher frequencies.
Adult ; Ear ; Ear Canal ; Ear Protective Devices ; Female ; Head ; Hearing ; Hearing Loss ; Hearing Loss, Unilateral ; Humans ; Iran ; Male ; Methods ; Noise

BACKGROUND AND OBJECTIVES: Magnetic resonance (MR) imaging has resulted in a tremendous advance in the technology of medical diagnosis. However, even with all positive advances, there are usually some negative aspects, especially noise. It is well known that loud sounds can induce a hearing loss. This study was performed to determine the acoustic characteristics of MRI noise and whether or not the sound exposure resulting from routine MRI examinations is capable of altering the auditory thresholds of patients. MATERIALS AND METHOD: Digital Impulse Sound Level Meter was placed at patient's head level and at a 2m distance. Frequency of MRI noise was recorded by Digital audio tape and analyzed by Computerized Sound Lab (CSL). A total of 53 adults (106 ears) who were scheduled for MR imaging studies were included in the study. Pure-tone air-conductive auditory threshold was determined bilaterally in each patient before and after MRI. RESULTS: The noise levels at head level ranged from 80.8 dB to 86.0 dB, and at a 2 m distance, from 71.9 dB to 75.9 dB. The frequency ranged from 60 Hz to 2500 Hz. Nine of the 106 ears had a hearing loss of at least 10 dB at one frequency. CONCLUSION: The noise generated by the MRI is sufficiently intense to cause some temporary threshold shifts (TTS). TTS may transform to permanent threshold shifts. Therefore, it is important to devise a method to minimize the risk of these shifts, for example, by using earplug.
Acoustics* ; Adult ; Auditory Threshold ; Diagnosis ; Ear ; Ear Protective Devices ; Head ; Hearing Loss* ; Hearing* ; Humans ; Magnetic Resonance Imaging* ; Noise*

PURPOSE: The purpose of this research was to analyze the effects of an eye protective device and ear protective device application on sleep disorder with coronary disease patients in CCU. METHODS: The research design was set up as a nonequivalent control group non-synchronized design. The subjects were coronary disease patients in the CCU of a tertiary hospital. The subjects were composed of 20 in the group with an eye protective device, 18 in the group with an ear protective device, 17 in the group with an eye protective device and ear protective device and 20 in the control group. The data was analyzed by chi-square-test, ANOVA, Repeated measures ANOVA, Sheffe-test, Simple main effect and Time contrast using SPSS Win 12.0. RESULTS: The hypothesis, 'There are significant differences in sleep quantity among the four groups' was supported (F=1,342.71, p=.000). The hypothesis, 'There are significant differences in the subjective evaluation of the general sleep patterns among the four groups' was supported (F=3,638.73, p=.000). In addition the hypothesis, 'There are significant differences in degree of sleep among the four groups' was supported (F=1,616.61, p=.000). CONCLUSION: It is cost effective and a simple eye protective device and ear protective device should be applied to patients according to their preference and characteristics in the clinical setting.
Aged ; Chi-Square Distribution ; Coronary Care Units ; Coronary Disease/*complications ; *Ear Protective Devices ; *Eye Protective Devices ; Female ; Health Facility Environment ; Humans ; Inpatients ; Lighting ; Male ; Middle Aged ; Noise ; Sleep Disorders/complications/*prevention & control

OBJECTIVES: To assess the protective effects of wearing protective devices among the residents and volunteers who participated in the cleanup of the Hebei Spirit oil spill. METHODS: A total of 288 residents and 724 volunteers were surveyed about symptoms, whether they were wearing protective devices and potential confounding variables. The questionnaires were administered from the second to the sixth week following the accident. Spot urine samples were collected and analyzed for metabolites of 4 volatile organic compounds (VOCs), 2 polycyclic aromatic hydrocarbons (PAHs), and 6 heavy metals. The association between the wearing of protective devices and various symptoms was assessed using a multiple logistic regression adjusted for confounding variables. A multiple generalized linear regression model adjusted for the covariates was used to test for a difference in least-square mean concentration of urinary biomarkers between residents who wore protective devices and those who did not. RESULTS: Thirty nine to 98% of the residents and 62-98% of volunteers wore protective devices. Levels of fatigue and fever were higher among residents not wearing masks than among those who did wear masks (odds ratio 4.5; 95% confidence interval 1.23-19.86). Urinary mercury levels were found to be significantly higher among residents not wearing work clothes or boots (p<0.05). CONCLUSIONS: Because the survey was not performed during the initial high-exposure period, no significant difference was found in metabolite levels between people who wore protective devices and those who did not, except for mercury, whose biological half-life is more than 6 weeks.
Adult ; Aged ; Biological Markers/urine ; *Disasters ; Environmental Exposure/*prevention & control ; Environmental Pollutants/*urine ; Female ; Gloves, Protective ; Humans ; Male ; Masks ; Metals, Heavy/urine ; Middle Aged ; Oceans and Seas ; *Petroleum ; Polycyclic Hydrocarbons, Aromatic/urine ; Protective Clothing ; *Protective Devices ; Respiratory Protective Devices ; Shoes ; Volatile Organic Compounds/urine ; Voluntary Workers

BACKGROUND AND OBJECTIVES: One of the major occupational hazards of working in the military service is being subjected to intense impulse noise, hence acoustic trauma. Acute acoustic trauma is a preventable disease, but the effective treatment modality has not been established yet. Acute acoustic traumas caused by exposure to rifle gunshot noise are common in young Korean males in the military service because of conscription policy. Through the analysis of the clinical presentation of acoustic traumas caused by rifle gunshot noise, we suggest effective preventive modalities. SUBJECTS AND METHOD: 165 soldiers who had otologic symptoms after performing regular rifle gunshot exercise without any hearing protective measures were analyzed. They all had been tested with K2 rifle. History taking, physical examination, pure-tone audiometry, and impedence audiometry, temporal MRI, and Newmann's tinnitus inventory questionnaire survey were performed. RESULTS: Most common and annoying symptom was tinnitus. The average outcome of postexposure air conduction thresholds were 22.3dB HL in the affected ear and 11.8dB HL in the unaffected ear. There was no correlation between severity of tinnitus and severity of hearing loss. Asymmetry of hearing loss related to head position during gunshot was not found. This may be due to the fact that during the mass gunshot training, each patient can be influenced by the gunshot noise of the adjacent gunner's shooting. CONCLUSION: Widening the distance between firing lanes and providing bilateral hearing protective devices against acoustic trauma must be taken into serious consideration.
Acoustics ; Audiometry ; Audiometry, Pure-Tone ; Ear ; Ear Protective Devices ; Fires ; Head ; Hearing ; Hearing Loss ; Hearing Loss, Noise-Induced ; Humans ; Male ; Military Personnel ; Noise ; Physical Examination ; Surveys and Questionnaires ; Tinnitus

BACKGROUND AND OBJECTIVES: Noise induced hearing loss (NIHL) is a preventive disease and yet the effective treatment modality has not been established. Acute acoustic traumas caused by an exposure to gunshot noise are common in young Korean males in the military service. Considering the significant lack of awareness on this serious issue as well as the absence of proper protection gears, an in-depth analysis is desperately needed. SUBJECTS AND METHOD: 3,650 soldiers performed a regular gunshot exercise without any hearing protective measures. Out of 3,650 soldiers, 8 patients with hearing impairment after the regular gunfire visited aeromedical squadron. They were all right-handed males: 7 had been tested with K-2 rifle and 1 had been tested with K-5 revolver. History taking, physical examination, pure-tone audiometry, and impedence audiometry were performed. In the next round of gunshot practice, all soldiers performed gunfire with unilateral hearing protection. RESULTS: The average outcome of postexposure air conduction thresholds were 6.5 dB in the right ear and 33.1 dB in left ear. After medical treatment, hearing impairment was much improved ; however, tinnitus was not diminished. In the next round of gunshot practice, the supplement of unilateral earplug protection proved its effectiveness on acoustic trauma caused by gunfire noise. CONCLUSION: Asymmetry of hearing loss was related to head position during gunfire. Unilateral hearing protection device was enough to protect hearing from acoustic trauma caused by gunshot. At the same time, it can effectively prevent a potential firearm accident that can be caused by trainees' mishearing the instruction of firearm instructor if both earplugs are worn. Thus, providing unilateral earplug protection against acoustic trauma must be taken into serious consideration.
Audiometry ; Audiometry, Pure-Tone ; Ear ; Ear Protective Devices ; Head ; Hearing Loss* ; Hearing Loss, Noise-Induced ; Hearing* ; Humans ; Male ; Military Personnel* ; Noise* ; Physical Examination ; Tinnitus