An Iranian study has found that hearing loss is quite common among heavy-vehicle drivers.
The study found that 26.8% of the heavy-vehicle drivers had hearing loss. 14.6% had hearing loss in both ears (bilateral hearing loss). 7.8% had hearing loss in the left ear and 4.4% had a hearing loss in the right ear (unilateral hearing loss). The rest (73.2%) did not have any significant hearing loss. Most of drivers with a hearing loss had a mild hearing loss.
The study was conducted among 65,533 heavy-vehicle drivers including truck and intercity bus drivers in Isfahan in Iran from February 2006 to March 2016. All participants were male.
Pure tone air and bone conduction audiometry parameters were used to test the hearing condition of people. Hearing loss was calculated as mean threshold pure tune at 0.5, 1, 2, 3, 4, 6 and 8 kHz in each ear.
Classification of hearing loss
Classification of people was based on hearing loss as: people with healthy ears (Hearing loss less than 25 dB), people with weak hearing loss (hearing loss higher than 25 dB and lower than 40 dB), people with medium hearing loss (hearing loss higher than 40 dB and lower than 60 dB) and people with high hearing loss (higher than 60 dB).
The study, "Prevalence hearing loss of truck and bus drivers in a cross-sectional study of 65,533 subjects", was published in the journal Environmental Health and Preventive Medicine.
Source: The journal Environmental Health and Preventive Medicine.