Aging and the Perceptual Organization of Sounds: A Change of Scene?

The peripheral and central auditory systems undergo tremendous changes with normal aging. In this review, we focus on the effects of age on processing complex acoustic signals (such as speech and music) amid other sounds, which requires a set of computations known as auditory scene analysis. Auditory scene analysis is the process whereby the brain assigns parts of the acoustic wave derived from an amalgamation of physical sound sources into perceptual objects (such as words or notes) or streams (such as ongoing speech or music). Solving the scene analysis problem, therefore, depends on listeners’ ability to perceptually organize sounds that occur simultaneously and sequentially. The perceptual organization of sounds is thought to involve low-level automatic processes that group sounds that are similar in physical attributes such as frequency, intensity, and location, as well as higher-level schema-driven processes that reflect listeners’ experience and knowledge of the auditory environment. In this chapter, we review prior research that has examined the effects of age on concurrent and sequential stream segregation. We will present evidence supporting the existence of an agerelated change in auditory scene analysis that appears to be limited to concurrent sound segregation. Evidence also suggests that older adults may rely more on schemadriven processes than young adults to solve the scene analysis problem. The usefulness of auditory scene analysis as a conceptual framework for interpreting and studying age-related changes in sound perception is discussed.