2010 BC Guide in Determining Fitness to Drive

Chapter 18: Hearing LossBACKGROUND18.1 About hearing lossHearing loss is categorized as either conductive or sensorineural. Conductive hearing lossinvolves abnormalities in the external or middle ear, including the ear canal, eardrum or ossicles.A blockage or other structural problem interferes with how sound gets conducted through theear, making sound levels seem lower. In many cases, conductive hearing loss can be correctedwith medication or surgery.Sensorineural hearing loss typically results from permanent damage to the inner ear (cochlea) orthe auditory nerve. Typically, it is gradual, bilateral, and characterized by the loss of highfrequencyhearing. Sensorineural hearing loss is permanent and often is helped with hearingaids. Profound deafness can be treated with cochlear implants.Sensorineural hearing loss accounts for 90% of all hearing loss.18.2 Prevalence and incidence of hearing lossThe 2003 Canadian Community Health Survey (CCHS) indicated that 3% of Canadians 12 yearsof age and older have some type of hearing difficulty. The prevalence of hearing loss increaseswith age. In the CCHS, 5% of 65 to 69 year-olds reported hearing problems, with the percentageincreasing to 23% of those 80 and older. Hearing loss is more common in men than in womenacross every age group.18.3 Hearing loss and adverse driving outcomesThe effects of hearing loss on the ability to safely operate a motor vehicle are not wellestablished. Although the overall body of literature examining the relationship between hearingloss and driving is small, since the 1990’s there has been an increasing amount of research in thisarea. The results are equivocal. Some studies report an association between impairments inhearing and adverse driving outcomes while others have not found an association.Although variability in methodology makes it difficult to draw conclusions across studies, resultsfrom studies indicate that, for the majority (70%) of study measures, no significant relationshipwas found between hearing loss and adverse driving outcomes (e.g. crashes, violations,convictions).219