This article summarizes the research findings from a longitudinal study of the language, speech, and social-emotional development of children who are deaf and hard of hearing, all of whom have hearing parents. This series of studies, from 1994 to the present, investigated predictors of successful developmental outcomes. The article provides information about how the findings of these studies relate to the existing literature. A description of the Colorado Home Intervention Program (CHIP) in which the participants were enrolled is also provided. During the course of these investigations, universal newborn hearing screening programs were established in Colorado, changing the age of identification of hearing loss and initiation into intervention in this program geared to families with infants and toddlers, birth through three years of age, from an average of 20 months of age to 2 months of age. Language development is positively and significantly affected by the age of identification of the hearing loss and age of initiation into intervention services. Both speech development and social-emotional variables are highly related to language development.