Development of Infant Stream Segregation: The Interplay Between Perception & Cognition

University Of Maryland, College Park, College Park MD

Investigators

Abstract

Infants sometimes hear speech in quiet settings, but oftentimes they must separate speech from many other sounds in the background (the television, the dishwasher, traffic, other people talking, and so on). It is remarkable that infants can separate speech from background noises so effectively, especially given research indicating that infants are unable to use the kinds of perceptual cues that adults use when perceiving speech. With support of the National Science Foundation, Dr. Newman is conducting a series of experiments on infant speech perception. The experiments are designed to investigate two types of perceptual cues that infants are hypothesized to use in separating speech from background noises: 1) voice qualities associated with the gender of a speaker, and 2) phonetic qualities associated with the language being spoken. Previous studies have shown that infants can distinguish between different voices and different languages only a few days after birth, so it is possible that the perceptual mechanisms used to make these distinctions are also used to more generally distinguish speech from background noises. However, different theories predict different results as a function of age, so the experiments will test infants at different ages to bring evidence to bear on the competing theories, thereby helping to refine and advance them. The research also has broader implications for understanding of how auditory and language systems develop in the formative years of infancy. Thus the basic knowledge created by this research promises to be informative for parents and other caregivers in terms of the impact that household sounds and other auditory distractions may have on infant development.