Background: Mothers facilitate their young hearing children's word learning by making reference explicit for novel words through physical designation (e.g., with deictic gestures) and by isolating words in simple syntactic frames. As children's language skills develop, such modifications decrease. Less is known about hearing mothers' support to their language-delayed deaf children. Aims: The current study investigated whether hearing mothers tailored their input to suit their deaf children's word-learning ability as well as their children's word knowledge. Methods & Procedures: Maternal input to 25 oral deaf children was examined. Word-learning ability was assessed in an experimental task that tested the children's ability to novel map (i.e., infer that a novel word refers to a novel object without physical designation). Word knowledge was assessed by maternal report. Outcome & Results: Mothers whose children did not infer word meaning through novel mapping made meaning more explicit than mothers of children who could learn through novel mapping. Specifically, these mothers were more likely to designate referents physically and use simple syntax. For all children, mothers were more likely to make the meaning of novel words more transparent than familiar words. Conclusions & Implications: The results indicate that hearing mothers were sensitive to the needs of their deaf children. This sensitivity was to children's word knowledge. Mothers seemed aware of what words were in their children's lexicon. Mothers did not rely on their children's ability to use novel mapping, even for the linguistically advanced children. (Contains 6 tables and 2 notes.)