Despite medical, technical, and pedagogical advances, the risk for language impairment is still much higher in deaf and hard-of-hearing (DHH) children than in hearing peers. Research on linguistic, cognitive, and communicative development in DHH children has found a range of basic spoken language deficits. Twenty percent to 50% of deaf children still meet criteria for language impairment. Tests of nonword repetition and verb inflection are markers that improve early identification of children at risk for persistent language problems. DHH children are typically mainstreamed today, and poor listening conditions in the classroom severely jeopardize learning in children with weak perceptual and cognitive skills. In this chapter we report on our own and others’ studies exploring the interaction of factors, both external and internal to the child, that influence spoken language and communication. The focus is on intervention projects aiming to improve language learning environments through teacher education.