At birth, infants already have in place a number of perceptual sensitivities that predispose them to attend to human speech and talking human faces and to represent core properties of each. Moreover, as early as the have been tested, infants can detect structural relations between heard, seen, and felt speech – all without prior specific experience. Coupled with powerful learning capabilities, these initial capacities allow infants to rapidly become expert perceivers,  and ultimately users of their native language. In this talk, I will explore the multisensory speech perception capabilities of the very young human infant, how these change across development and learning to map on to the characteristics of the native language (languages in the case of the bilingual infants), all within a framework of how cascading critical periods might act to gate and/or amplify experience. The theoretical and applied implications of this work will be discussed.