Talker variability in speech influences language processing from infancy through adulthood and is inextricably embedded in the very cues that identify speech sounds. Yet little is known about developmental changes in the processing of talker information. On one account, children have not yet learned to separate speech sound variability from talker-varying cues in speech, making them more sensitive than adults to talker variation. A different account is that children are less developed than adults at recognizing speech sounds and at recognizing talkers, and development involves protracted tuning of both recognition systems. The current research presented preschoolers and adults (N = 180) with voices linked to two distinct cartoon characters. After exposure, participants heard each talker and selected which character was speaking. Consistent with the protracted tuning hypothesis, children were much less accurate than adults when talkers were matched on age, gender, and dialect (Experiments 1-3), even when prosody differed (Experiment 5). Children were highly accurate when voices differed in gender (Experiment 2) or age (mother vs. daughter; Experiment 6), suggesting that greater acoustic dissimilarity facilitated encoding. Implications for speech sound processing are discussed, as are the roles of language knowledge and the nature of talker perceptual space in talker encoding. (Contains 6 figures and 1 table.)