We examine how native lexical-tone experience influences identification of novel tone. Cantonese, Thai, Mandarin, and Yoruba listeners identified CV syllables bearing the six phonemic Cantonese tones. Accuracy scores were submitted to a two-way rANOVA with L1-Group (x4) as the between-subjects factor and Tone (x6) as the within-subjects factor. Tone error patterns were also assessed via rANOVAs with L1-Group (x4) as the between-subjects factor and Response-Pattern (% correct versus % other response) as the within-subjects factor. Consistent with previous reports, native listeners’ confusions reflected effects of ongoing tonal mergers and a crowded tone space. Non-native listeners appeared to assimilate novel tones to L1 tone categories by attending to phonetic cues relevant to the phonological and phonetic properties of their L1s. Overall, results support predictions of the Perceptual Assimilation Model for Suprasegmentals (PAM-S). [Support: NSF grant 0965227 to J.A.A.]