What is the impact of an infants diminished hearing on the infant and its parents? How does communication develop in cases of diminished hearing? How does diminished hearing affect social and cognitive development? What types of early interventions can improve communication and development in infants with diminished hearing? The World of Deaf Infants presents the results of a 15-year research study that addresses these questions. Through their research, perhaps the largest, long-term comparison of deaf and hearing infants, Meadow-Orlanss team provides a comprehensive and intimate look into the world of deaf infants. For a core group of 80 families that includs all four combinations of parent-infant hearing status, data was collected longitudinally at 9, 12, 15, and 18 months, and mother-infant interactions were recorded and observed in both structured and unstructured settings. Mothers facial, vocal, and tactile behaviors during interactions were related to infants temperament and stress; mothers linguistic and communication behaviors, as well as their overall responsiveness, were related to childrens language; and the effects of support provided to mothers were evaluated and explored. The results were dramatic, particularly those on infant attachment behaviors and the importance of visual attention to the overall development of deaf infants. This comprehensive work provides a foundation on which researchers, teachers, students, and parents can build to improve communication, cognitive and social development, and to enhance the world of deaf infants.