Young 2-year-olds' interpretation of a novel noun was influenced by preexposure to similar-sounding words. In Experiment 1, 16 children selected an unfamiliar rather than a familiar object as the noun's referent more often when they had just heard many words that sounded like it than when they had just heard many that did not. Exposure to repeated sounds was hypothesized to reduce the attentional resources needed to process a word made up ofthe sounds, permitting extra resources to be applied to the name mapping problem. In Experiments 2 and 3, exposure had a similar effect on children's mapping of a novel noun that sounded similar to the name of the familiar choice object (e.g., their mapping of wug onto a stethoscope rather than dog). Exposure was hypothesized to cause differences perceived within the set of words to be magnified and those perceived outside of it to be reduced.