OBJECTIVES: To investigate the relation between different types of exposure to noise and a classic sign of noise-induced hearing loss (NIHL); the audiometric notch. METHODS: A cross-sectional epidemiological survey was carried out in electronics sound inspectors exposed to continuous and impulsive type noises. The noise levels in the working environments, and the audiometric hearing threshold levels were measured. RESULTS: Electronics sound inspectors were exposed to impulsive noise ranging from 74.1 to 88.9 dBA. The hearing loss induced by impulsive noise was greater and was characterized by maximum loss at 6 kHz audiometric frequency, as opposed to the notch at 4 kHz that is typical of continuous noise. CONCLUSIONS: The results suggest that the probable effect of impulsive noise on hearing should be considered even when the exposure is within the 85 dB equivalent A-weighted level. To diagnose NIHL it is important to elicit a detailed and accurate history of exposure to noise. Although the notch at 4 kHz is a well established clinical sign and may be valuable in confirming the diagnosis, the 6 kHz notch is variable and of limited importance.
Diagnosis ; Hearing Loss ; Hearing Loss, Noise-Induced ; Hearing* ; Noise*

China ; Hearing Loss, Noise-Induced ; diagnosis ; Humans ; Occupational Diseases ; diagnosis

Hearing Loss, Noise-Induced ; diagnosis ; therapy ; Humans ; Miners ; Mining ; Noise ; adverse effects

Female ; Hearing Loss, Noise-Induced ; diagnosis ; Humans ; Leisure Activities ; Male ; Music ; Noise ; adverse effects

Female ; Hearing Loss, Noise-Induced ; diagnosis ; Humans ; Leisure Activities ; Male ; Music ; Noise ; adverse effects

Hearing Loss, Noise-Induced ; diagnosis ; etiology ; Humans ; Noise, Occupational ; adverse effects ; Reference Standards

Hearing Loss, Noise-Induced ; diagnosis ; etiology ; Humans ; Noise, Occupational ; adverse effects ; Reference Standards

Although noise-induced hearing loss (NIHL) is the most prevalent occupational disease in Korea, only 10% of the diagnosed cases are compensated. Old (1989-94) and current diagnostic criteria, criteria for workers' compensation of NIHL in Korea, compensation formulas of American Medical Association/American association of Ophthalmology and Otolaryngology (AMA/AAOO), the Committee on Hearing, Bio-Acoustics, Biomechanics (CHABA), American Academy of Otolaryngology (AAO) recommendation were compared. Each criterion was applied on the audiomety data of 4044 workers (8023 ears), who had received the second line screening test of Special Periodic Health Examination Program for noise-exposed workers during 1991-2. First, the resulting proportions of NIHL cases by employing each criterion were compared and strength of agreement was measured using kappa value. Temporary Threshold Shift (TTS) was corrected by noise free interval, and the reduction ratio of NIHL cases was calculated. Theoretical progression model of NIHL was reconstructed from previous studies on the natural course of NIHL to evaluate the change of diagnosis result of each criterion in the model. The kappa value between old and current criteria was 0.19, 0.55 for current criteria and workers' corn. criteria, ranging from 0.08 to 0.78, highest coincidence was observed between current criteria and CHABA formula. The current criteria produce most similar results with CHABA formula. If TTS is corrected for NFI, there is about 14 % reduction of NIHL cases. The results of applying on NIHL progression model divided the formulas roughly into 3 groups, of which compensation criteria was the most, old criteria and AAO the least conservative. In conclusion. The result of 4 KHZ audiometry should be excluded in evaluation of hearing level and a new hearing conservation program should be set out. Current diagnostic criteria has an ambiguity in that managerial concept for prevention arid! purpose of compensation is mixed up. The current diagnostic criteria and compensation criteria could be incorporated'into 'a new formula which is based on the state of the art test for estimating everyday hearing disability.
Audiometry ; Compensation and Redress ; Diagnosis ; Hearing Loss* ; Hearing Loss, Noise-Induced ; Hearing* ; Korea* ; Mass Screening ; Noise* ; Occupational Diseases ; Ophthalmology ; Otolaryngology ; Workers' Compensation ; Zea mays

Adult ; Female ; Hearing Loss, Noise-Induced ; diagnosis ; etiology ; Humans ; Male ; Middle Aged ; Noise, Occupational ; adverse effects ; Occupational Diseases ; diagnosis ; etiology

Objective: To explore the change of hearing threshold of workers exposed to noise, establish an individual-based hearing loss early warning model, accurately and differentiated the health of workers exposed to noise. Methods: In September 2019, all physical examination data of 561 workers exposed to noise from an enterprise were collected since their employment. Three indicators of average hearing threshold of the better ear, namely, at high frequency, 4000 Hz and speech frequency, were constructed. The generalized estimating equation (GEE) was used to adjust gender and age and establish the warning model of each indicator. Finally, sensitive indicators and warning models were screened according to AUC and Yoden index. Results: Among the 561 workers exposed to noise, 26 (4.6%) workers had hearing loss. The sensitivity indicators were the average hearing threshold at speech frequency ≥20 dB, high frequency ≥30 dB and 4000 Hz ≥25 dB. The AUC of each index was 0.602, 0.794 and 0.804, and the Youden indexes were 0.204, 0.588 and 0.608, respectively. In GEE of hearing loss warning models, high-frequency hearing threshold ≥20 dB and 4000 Hz hearing threshold ≥25 dB were the optimal models, with AUC of 0.862. Conclusion: Combined with the changes of individual hearing threshold over the years, can accurately assess the risk of individual hearing loss of workers exposed to noise.
Humans ; Hearing Loss, Noise-Induced/diagnosis* ; Noise, Occupational/adverse effects* ; Audiometry ; Deafness ; Employment ; Occupational Exposure/adverse effects* ; Occupational Diseases/diagnosis*