Human speech is a highly complex sound; whose perceptual processing, production and relations to language and cognition require an integrated analysis, not only from the viewpoint of available knowledge but also of its methodological specificities. This article presents a brief review of the literature on the main acquisitions and development of language in the first year of life of normally developing infants, with emphasis on speech perception. One also analyzes the occurrence of auditory disturbances in the first year of life that could jeopardize speech perception, with possible implications for pre-linguistic development. Special attention is give to the development of speech perception and language in Down syndrome infants. The predisposition to audiologic problems, its relation to impairment in the development of language, and the tendency presented in the first year of life of differential patterns of attention to speech is analyzed in this population.
speech perception; development; infants; language; down syndrome