Grant: Project Grant

In Canada, an estimated 7 million people suffer from debilitating hearing loss. Consequences of hearing loss are far-reaching and include high rates of social isolation, depression, and more recently has been identified as the greatest modifiable risk factor for dementia. Fortunately, with the advent of the cochlear implant (CI), people with severe hearing loss can have their hearing restored to some degree. A CI is a surgically implanted device that provides electrical stimulation of the auditory nerve feeding the auditory centres of the brain. It significantly enhances hearing, though there is substantial variability in speech perception and quality of life outcome. The underlying causes of this variability are not well understood. It has become clear that how we typically measure "outcome" is not optimal. For example, standard clinical measures that test abilities to detect simple sounds at the doctor's office often have little predictive value of how the CI improves speech perception in everyday life. The overall goal of this project is to develop and test new behavioural and neurophysiological methods using a realistic and ecologically valid framework. We believe that the use of realistic listening conditions will yield strong relationships with everyday accounts. We will use behavioural methods that quantify one's ability to separate different talkers and to remember what was said. We will use recently developed methods to quantify how well the brain can "track" different speech streams mimicking how we follow natural conversations. These novel findings can lead to more precise and patient-based rehabilitation in people with hearing loss and provide metrics when assessing those who may be at risk for developing dementia.