The present paper discusses research investigating adult listeners' perceptual learning of talker- and accent-specific properties of spoken language. Traditionally, neural and behavioral plasticity in speech perception was assumed to end with childhood and/or adolescence. However, recent research suggests that adult listeners are sensitive to a variety of talker-specific properties of speech and that perceptual processing of speech changes as a function of exposure to and familiarity with these properties. Mechanisms involved in perceptual learning and change in speech processing were examined by evaluating the effects of exposure to foreign accented speech. Adult native speakers of American English were asked to transcribe English words produced by six native Spanish-speaking adults (three male and three female). Prior to this transcription task, listeners were exposed to a onehour training session with items produced by either the same Spanish-accented talkers as heard during the transcription task, a different set of six Spanish-accented talkers, or a different set of native American English talkers. A control condition with no training was also included. The results showed that listeners were most accurate when transcribing Spanish-accented speech at test if they had been exposed to Spanish-accented speech during training. In addition, listeners were more accurate when transcribing items produced by the specific Spanish-accented talkers they had heard during training than when transcribing items produced by different Spanish-accented talkers. Additional experiments examining the role of training and stimulus form on perceptual learning and generalization will also be reported. The results suggest that even brief exposure to both talker-specific and accent-specific properties of speech significantly changes the way in which adult listeners perceive speech. Adult listeners perceptually adapt to idiosyncratic characteristics of individual talkers as well as to systematic properties of non-native speech patterns suggesting that listeners are sensitive to both talker-specific and accent-general regularities in spoken language. These findings provide support for behavioral and representational plasticity in speech perception in adult listeners.