This comprehensive collection of current research in the development of speech perception and perceptual learning documents the striking changes that take place both in early childhood and throughout life and speculates about the mechanisms responsible for those changes. The findings reported from this rich and active field address the role of growing linguistic knowledge and experience and demonstrate that speech perception develops in a bidirectional interplay with several levels of linguistic structure and cognitive processes. Examining transitions in the perceptual processing of speech from infancy to adulthood as well as what causes these transitions, the contributors take up a broad range of issues that are central to constructing a theory of speech perception and to understanding the development of this ability. These include the nature of infants' early sensory proficiencies, how these skills come to support the recognition of linguistic units, developmental differences in the representation and processing of linguistic units, the acquisition of early word patterns and a phonological system, and the mechanisms behind perceptual learning. The Development of Speech Perception is unique in attempting to integrate research involving infants, young children, and adults and in its thorough treatment of developmental issues in speech perception. It systematically explores how adult perceptual abilities begin to develop from early infant capabilities, and in doing so addresses several levels of linguistic processing.