We examined mothers' speech to 2-year-old children in both quiet and moderately noisy conditions. Mothers were recorded while teaching their children two words, one of which occurred in the context of other people speaking. Parents used characteristics of infant-directed speech (IDS) to these older children. Even more interesting was that many of the prosodic changes typical in IDS were accentuated in noise. In a context in which multiple people were speaking simultaneously, mothers spoke to their children with both increased pitch and increased word duration relative to when they spoke in a quiet condition. However, these changes were quite small, lending only mixed support to proposals that one of the advantages of IDS is that it is easier to separate from background noise.