This paper provides a selective overview of some of the research that has followed from the publication of Werker and Tees (1984a) "Cross-language speech perception: Evidence for Perceptual Reorganization During the First Year of Life." Specifically, I briefly present the original finding, our interpretation of its meaning, and some key replications and extensions. I then review some of the work that has followed, including work with different kinds of populations, different kinds of speech sound contrasts, as well as attunement (perceptual reorganization) to additional properties of language beyond phonetic contrasts. Included is the body of work that queries whether perceptual attunement is a critical period phenomenon. Potential learning mechanisms for how experience functions to guide phonetic perceptual development are also presented, as is work on the relation between speech perception and word learning.