Abstract: Everyday hearing requires solving the cocktail-party problem, or segregating and attending to the relevant parts of complex auditory scenes. There are huge individual differences in cocktail-party listening abilities. People with clinical hearing loss generally struggle with cocktail-party listening due to impaired basic auditory sensitivity; however, others experience similar difficulties despite having “normal” sensitivity. Conventional wisdom says that such individual differences are due to a combination of genetic and environmental factors, although the specific factors and their relative weights are poorly understood. This talk will describe preliminary work and future plans to identify specific genetic and environmental factors influencing hearing abilities, including basic auditory sensitivity and cocktail-party listening. We will also discuss how these abilities relate to cognition, with a view towards leveraging these relationships to better understand the distinct and shared etiologies of presbycusis, cognitive decline, and dementia.