بررسی وضعیت شنوایی لوکوموتیورانان راه آهن یزد در سال 1390

Background: Noise-induced hearing loss is a sensorineural hearing loss, which is associated with exposure to high levels of sound. Since train drivers exposed to high noise levels and the use of hearing protection devices is relatively difficult and they also need to hear the radio communications, this study examines the hearing status of train drivers of Yazd Railway Company. Methods: This is a descriptive - analytical cross sectional study, which was performed on 153 train drivers. The results were compared with a control group of 148 office workers. After examination and blood tests, audiometry was performed for each subject by an audiologist and the data was analysis with SPSS software (ver.19). Results: The mean age of the train drivers and control group were 35.8±8.3 and 35.3±6.3 years respectively. Prevalence of high frequency sensorineural hearing loss among train drivers was 21.3% (29 patients), that was significantly higher than the control group. Prevalence of high frequency notch in the right ear in train drivers was 9.6% (13 patients) and 2.9% (4 patients) in the control group (p-value <0.02) and prevalence of notch in left ear was 14% (19 patients ) and, 3.7% (5 persons) in train drivers and control group respectively (p-value<0.003). In train drivers average hearing thresholds of high frequencies was higher in the left ear than the right ear (p-value=0.02). Conclusion: The high level of noise in the train drivers' cabin increases average hearing thresholds at high frequencies especially at 6000 Hz. The results also show that in noisy environment, left ear is more sensitive than the right ear.