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.