The accuracy of self-reported high noise exposure level and hearing loss in a working population in Eastern Saudi Arabia.
Journal - International journal of hygiene and environmental health (Germany )
OBJECTIVE: To determine the accuracy of questions in identifying subjects occupationally exposed to high noise level and those with hearing loss using noise dosimeter and pure-tone air conduction audiometry as the gold standards. DESIGN: A cross-sectional study involving 259 noise-exposed workers selected randomly from two factories in Eastern Saudi Arabia. Personal noise exposure was determined using a noise dosimeter. The hearing impairment for each subject was assessed using otoscopic examination and audiometry. Each subject completed a comprehensive questionnaire including questions about noise exposure and hearing loss. RESULTS: Eighty five percent of the total workers reported exposure to high noise level, compared to 76% found to be exposed to a high noise level defined as more than 85 dB (A) as determined by noise dosimeter. The prevalence of audiometric hearing loss (threshold average of 25 dB HL or more in any ear) was 32.4% for the low frequency average (0.5, 1 and 2 kHz), 47.9% for the all frequency average (0.5, 1, 2. 4 and 8 kHz) and 65.6% for the high frequency average (4 and 8 kHz). However, the percentage of the subjects who reported hearing loss ranged between 3.9% and 85.3% depending on the question used as indicator of hearing loss. The question "Do you consider the noise level where you are working now high?" was the most sensitive in correctly identifying subjects exposed to a noise level of more than 85 dB (A) (sensitivity = 93.4%) and subjects with hearing loss (sensitivity > 86%) compared with other questions evaluated. However, it overestimated the prevalence rate determined by audiometry. CONCLUSION: We conclude that in industries where facilities for an objective assessment of noise exposure and hearing loss are not available, questions addressing noise exposure and hearing loss might be a useful alternative means for screening subjects exposed to high noise level and those with hearing loss for the purpose of designing and implementing hearing conservation program.
|ISSN : ||1438-4639|
|Mesh Heading : ||Adult Audiometry Cross-Sectional Studies Health Surveys Hearing Loss Humans Industry Male Mental Recall Noise, Occupational Prevalence Reproducibility of Results Saudi Arabia epidemiology|
|Mesh Heading Relevant : ||Questionnaires epidemiology etiology adverse effects|
Occupational noise exposure and hearing loss of workers in two plants in eastern Saudi Arabia.
Journal - The Annals of occupational hygiene (England )
OBJECTIVE: To determine the prevalence of hearing loss associated with occupational noise exposure and other risk factors. DESIGN: A cross-sectional study involving 269 exposed and 99 non-exposed subjects (non-industrial noise exposed subjects) randomly selected. Current noise exposure was estimated using both sound level meter and noise-dosimeter. Past noise exposure was estimated by interview questionnaire. Otoscopic examination and conventional frequency (0.25-8 kHz) audiometry were used to assess the hearing loss in each subject. RESULTS: 75% (202 subjects) from the exposed group were exposed to a daily Leq above the permissible level of 85 dB(A) and most (61%) of these did not and had never used any form of hearing protection. Hearing loss was found to be bilateral and symmetrical in both groups. Bivariate analysis showed a significant hearing loss in the exposed vs non-exposed subjects with a characteristic dip at 4 kHz. Thirty eight percent of exposed subjects had hearing impairment, which was an 8-fold higher rate than that found for non-exposed subjects. Multivariate analysis indicated exposure to noise was the primary, and age the secondary predictor of hearing loss. Odds of hearing impairment were lower for a small sub-group of exposed workers using hearing protection (N=19) in which logistic regression analysis showed the probability of workers adopting hearing protective devices increased with noise exposure, education, and awareness of noise control. Hearing loss was also greater amongst those who used headphones to listen to recorded cassettes. CONCLUSION: Gross occupational exposure to noise has been demonstrated to cause hearing loss and the authors believe that occupational hearing loss in Saudi Arabia is a widespread problem. Strategies of noise assessment and control are introduced which may help improve the work environment.
|ISSN : ||0003-4878|
|Mesh Heading : ||Adult Cross-Sectional Studies Hearing Loss, Noise-Induced Humans Male Multivariate Analysis Prevalence Regression Analysis Risk Assessment Risk Factors Saudi Arabia epidemiology|
|Mesh Heading Relevant : ||Noise, Occupational epidemiology|
High-frequency (10-18 kHz) hearing thresholds: reliability, and effects of age and occupational noise exposure.
Journal - Occupational medicine (Oxford, England) (England )
The objective was to investigate the reliability and effects of age and noise on high-frequency hearing thresholds. A cross-sectional study was used involving 187 exposed and 52 non-industrial noise-exposed subjects selected randomly from noise-exposed and non-industrial noise-exposed subjects, respectively. Each subject was tested with both conventional-frequency (0.25-8 kHz) and high-frequency (10-18 kHz) audiometry. Test-retest results showed that high-frequency audiometry (HFA) was as reliable as the conventional procedure. Although the inter-subject variation was large, the intra-subject variation was small, indicating that HFA can be used more reliably than the conventional procedure to monitor individual cases over time. Both the hearing threshold at high frequencies and the upper frequency limit deteriorated as a function of age and frequency. The exposed subjects had significantly higher hearing thresholds than the non-exposed subjects at all the high frequencies tested, the difference between the two groups being greatest at 14 kHz. Multivariate analysis indicated that age was the primary predictor and noise exposure the secondary predictor of hearing thresholds in a high frequency range (10-18 kHz). In contrast, multivariate analysis indicated the reverse order-noise exposure as the primary predictor, then age-for a conventional frequency range (0.25-8 kHz). The results of this study suggest that HFA might be used as an early indicator for noise-induced hearing loss and acoustic trauma rather than audiometry at a conventional frequency (4 kHz), particularly for younger groups.
|ISSN : ||0962-7480|
|Mesh Heading : ||Adolescent Adult Age Factors Analysis of Variance Audiometry Auditory Threshold Hearing Hearing Loss, Noise-Induced Humans Linear Models Male Noise, Occupational Occupational Exposure Predictive Value of Tests methods physiology statistics & numerical data|
|Mesh Heading Relevant : ||physiology diagnosis adverse effects adverse effects|